Systems and Mehtods for Treating Obesity and Type 2 Diabetes

ABSTRACT

The present invention provides systems and methods for treating wounds in patients who lack the innate ability to regulate glucose (e.g., diabetic patients). In one aspect of the invention, a method includes positioning an internal bypass device within the duodenum to inhibit contact between chyme passing therethrough and an internal wall of the duodenum and maintaining the internal bypass device within the duodenum for a sufficient period of time to decrease insulin resistance and reduce a blood glucose level in the patient. The internal bypass device increases peripheral blood flow and elevates an immune system response to accelerate healing of the wound.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part to U.S. patent applicationSer. No. 12/566,193 filed Sep. 24, 2009, which claims the benefit ofU.S. Provisional Patent Application Ser. No. 61/239,506 filed Sep. 3,2009 and is also a continuation-in-part to U.S. patent application Ser.No. 12/508,701 filed Jul. 24, 2009, which claims the benefit of U.S.Provisional Patent Application Ser. No. 61/222,206 filed Jul. 1, 2009,the full disclosures of which are incorporated herein by reference forall purposes.

BACKGROUND OF THE INVENTION

The present invention relates to the field of obesity and diabetes andmore specifically to minimally invasive systems and methods forcontrolling or treating obesity and/or type 2 diabetes.

Obesity is one of the leading preventable causes of death worldwide andhas become a global epidemic affecting more than 400 million people. Inthe United States alone, approximately 300,000 obesity-linked deathsoccur annually, and obesity-related co-morbities lead to nearly $150billion in healthcare spending. Obesity is a medical conditionassociated with many subsequent diseases, including type-II diabetes,cardiovascular disease, sleep apnea and certain types of cancer. Theseconditions often have severe adverse effects on overall health, reducequality of life, limit productivity, lead to significant medical costs,and can ultimately lead to reduced life expectancy.

While obesity has a range of contributing causes, the vast majority ofobese individuals are obese because they overeat, fail to exerciseadequately, and in some cases have genetic predispositions to weightgain. The primary treatment for obesity is dieting, routine physicalexercise, and in some cases pharmacologic therapy. Obesity surgery,including irreversible Roux-en-Y gastric bypass (RYGB) and LaparoscopicAdjustable Gastric Banding (LAGB), involves surgical restriction of thestomach. These interventions are typically directed at either (i)reducing the caloric intake of the patient by triggering the satietyimpulse more rapidly or physically removing the ability of theindividual to ingest more than a limited amount of food, or (ii)inhibiting the ability of the individual's digestive system to extractthe full caloric value of the food being eaten.

The current surgical treatments for obesity, although often effective inachieving sustainable weight loss and thus reducing associatedco-morbidities, involve gross anatomical reconstruction of the digestivesystem, which may be irreversible. Unfortunately, as has become widelypublicized in the print and broadcast media, there can be significantadverse events, complications, and/or mortality associated with the mostradical of these procedures (including but not limited to RYGB). In alarge number of patients, subsequent surgical procedure(s) are requiredto address the complication(s) from the original surgery. While use ofRYGB and LAGB are approved for individuals with lower BMIs (i.e., <40),the risks associated with the procedures have limited their adoptionand/or use to only the morbidly obese population (>40 BMI). Recentreports indicate that there is a need to expand the options for obesitysurgery in order to provide safer alternatives for individuals who arenot prepared to risk the adverse consequences of radical RYGB and LAGBsurgery, but for whom a surgical intervention is wholly appropriate. Infact, many individuals who could benefit from surgical interventionbefore their excess weight results in serious health problems foregosurgery due to the significant complications and high rates of long-termadverse events leading to poor quality of life. Thus, there is a growingneed for an effective and safe alternative to obesity surgery for theobese patient population worldwide.

Diabetes mellitus type 2 or type 2 diabetes is a disorder that ischaracterized by high blood glucose in the context of insulin resistanceand relative insulin deficiency. There are an estimated 23.6 millionpeople in the U.S. (7.8% of the population) with diabetes with 17.9million being diagnosed, 90% of whom are type 2. With prevalence ratesdoubling between 1990 and 2005, CDC has characterized the increase as anepidemic. Traditionally considered a disease of adults, type 2 diabetesis increasingly diagnosed in children in parallel to rising obesityrates due to alterations in dietary patterns as well as in life stylesduring childhood.

Type 2 diabetes is a chronic, progressive disease that has noestablished cure, but does have well-established treatments which candelay or mitigate the inevitable consequences of the condition. Often,the disease is viewed as progressive since poor management of bloodsugar leads to a myriad of steadily worsening complications. However, ifblood sugar is properly maintained, then the disease is effectivelycured—that is, patients are at no heightened risk for neuropathy,blindness, or any other high blood sugar complication. Type 2 isinitially treated by adjustments in diet and exercise, and by weightloss, most especially in obese patients. The amount of weight loss whichimproves the clinical picture is sometimes modest (2-5 kg or 4.4-11 lb);this is almost certainly due to currently poorly understood aspects offat tissue activity, for instance chemical signaling (especially invisceral fat tissue in and around abdominal organs).

Gastric bypass procedures typically entail surgical restriction of thesize of the stomach and rerouting or bypassing a proximal portion theintestine to reduce absorption of nutrients. A study of 20-years ofgastric bypass patients found that 80% of those with type 2 diabetesbefore surgery no longer required insulin or oral agents to maintainnormal glucose levels. Weight loss also occurred rapidly in many peoplein the study who had had the surgery. Unfortunately, gastric bypassprocedures involve irreversible reconstruction of gastrointestinalanatomy and may be associated with significant adverse events, and/ormortality. In spite of the growth in the number of surgical proceduresfor weight loss (greater than 250,000 annually in the US), only 1.2% ofeligible patients elect to undergo these invasive surgeries each year.

Many patients who could benefit from these procedures forego surgery dueto the significant complications and high rates of long-term adverseevents leading to poor quality of life. The estimated 0.3-2% mortalityrate along with the 19% surgical complication rate for RYGB have beenmajor barriers for expanding the use of surgery in broader patientpopulations.

In view of the foregoing, there is a need in the art for new devices andmethods for controlling and treating obesity and type 2 diabetes.

SUMMARY OF THE INVENTION

The present invention provides systems, apparatus and methods fortreating wounds in patients, particularly chronic lower limb wounds inpatients lacking the innate ability to regulate glucose (e.g., diabeticpatients). In one aspect of the invention, a method for treating woundsincludes positioning a flexible sleeve within the patient such that thesleeve extends through at least a portion of the duodenum to inhibitcontact between chyme passing therethrough and at least a portion of aninner surface of the duodenum. The hollow sleeve is maintained withinthe duodenum for a sufficient period of time to reduce a blood glucoselevel in the patient. Preferably, the sleeve will be maintained inposition for a sufficient period of time to permit the normalization ofblood glucose levels in the patient (i.e., reducing such glucose levelsto below about 150 mg, preferably below about 125 mg).

The sleeve creates an “internal bypass” that substantially inhibitscontact between chyme and other substances entering the duodenum fromthe stomach of the patient and the bypassed portion of the duodenum.This reduces hormonal triggers that help to down-regulate the productionof glucose, thereby resulting in the relief of certain symptoms thatinhibit the body from effectively healing the wound, such as decreasedperipheral vascular perfusion, neuropathy, a compromised or “inactive”immune system and a reduction in important components of healing, suchas nitric oxide, vascular endothelial growth factors and the like.

In certain embodiments, the sleeve will be maintained in position for asufficient period of time to increase the peripheral vascular perfusionin the patient. Patients lacking the innate ability to regulate glucoselevels often suffer from decreased arterial perfusion of theextremities. The lack of blood flow to the extremities inhibits healingof wounds, such as foot ulcers and the like. In one embodiment of thepresent invention, the flexible sleeve is held in position within theduodenum until this process begins to reverse, thereby increasingperipheral vascular perfusion and allowing for accelerated healing ofthe wound.

In other embodiments, the sleeve will be maintained in position for asufficient period of time to elevate an immune system response in thepatient. Abnormally high glucose levels cause the body's immune systemto become compromised or less active than normal. The white blood cellsor leukocytes of the immune system that defend the body againstinfection become sluggish and unable to effectively fight infections,such as those associated with wounds. In this embodiment, the flexiblesleeve is held in position within the duodenum until the activity ofcirculating leukocytes begins to substantially increase, which allowsthe patient's immune system to do its natural job of fighting theinfection and accelerate healing of the wound.

In other embodiments, the flexible sleeve is maintained in position fora sufficient period of time to increase certain healing factors, such asnitric oxide and vascular endothelial growth factors (VEGF) in thepatient. VEGF is an important signaling protein that stimulates thegrowth of new blood vessels, which can be a critical part of theangiogenesis process in wound healing.

In one embodiment of the present invention, the flexible sleeve is heldin position within the duodenum until a sufficient amount of VEGF areproduced in the patient to accelerate healing of the wound.

In other embodiments, the flexible sleeve will be maintained in positionfor a sufficient period of time to halt or reverse neuropathy. Diabeticneuropathy is a common complication of patients lacking the innateability to regulate glucose in which nerves are temporarily orpermanently damaged as a result of high blood sugar levels(hyperglycemia). Neuropathy can complicate the wound healing process,particularly in the extremities. In this embodiment, the sleeve is heldin position until nerves that have not been permanently damaged ordestroyed can be repaired by the body to accelerate healing of thewound.

In a preferred embodiment, the flexible sleeve is sized and shaped toextend from the distal opening of the duodenal anchor through theduodenum and into a proximal portion of the jejunum of the patient. Thesleeve is substantially hollow and positioned such that partiallydigested food, i.e. chyme, moving through the digestive tract passesthrough the interior of the sleeve. This inhibits the absorption ofnutrients/calories in the upper segments of the small intestine anddelays mixing of chyme with digestive enzymes such that a quantity offood ingested by the patient will have a smaller caloric value with thesleeve in place. In addition, it is believed that the sleeve inhibitscertain hormonal triggers that would otherwise occur when food passesthrough the duodenum and proximal jejunum; hormonal triggers that causethe body to become insulin resistant and result in type 2 diabetes.

In certain embodiments, the sleeve is removably introduced through anatural orifice in the patient into the small intestines, preferablyendoscopically through the patient's esophagus, stomach and pylorus. Thesleeve can be maintained in position within the duodenum in a variety ofways known to those of skill in the art (e.g., sutures, hooks, barbs,atraumatic anchoring mechanisms and the like), typically for about 2weeks to one year, preferably between about 1 month to 6 months and morepreferably between about 6-12 weeks.

In a preferred embodiment, the sleeve is maintained in position with apair of anchor elements flexibly coupled to each other and the sleeve.In the preferred embodiment, the flexible anchors are endoscopicallyintroduced with the sleeve and positioned on either side of the pylorus.The duodenal anchor element is preferably expanded to a size that willinhibit proximal movement of the duodenal anchor through the pyloricsphincter to ensure that the sleeve remains in the patient's intestines.Likewise, the gastric anchor element is expanded to a size that willinhibit or prevent distal movement through the pyloric sphincter toensure that the device does not pass further into the intestines andcreate a blockage. In a preferred embodiment, the anchor elements areexpanded by delivering a fluid into each anchor element to inflate saidanchors. In other embodiments, the anchor elements may be expandedmechanically or by other suitable means.

Other aspects, features, advantages, etc. will become apparent to oneskilled in the art when the description of the invention herein is takenin conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

For the purposes of illustrating the various aspects of the invention,there are shown in the drawings forms that are presently preferred, itbeing understood, however, that the invention is not limited by or tothe precise data, methodologies, arrangements and instrumentalitiesshown, but rather only by the claims.

FIG. 1 is a view of a portion of a normal GI tract of a human;

FIG. 2 is a perspective view of a bypass device in an operativeconfiguration according to one embodiment of the present invention;

FIG. 3 is a cross-sectional view of a gastric anchor of the bypassdevice of FIG. 2;

FIG. 4 is a top view of an alternative embodiment of a gastric anchoraccording to the present invention;

FIG. 5 illustrates a distal end of a hollow sleeve according to thepresent invention;

FIG. 6 is a cross-sectional view of an alternative embodiment of aduodenal anchor according to the present invention;

FIG. 7 is a top view of the duodenal anchor of FIG. 6;

FIG. 8 is a perspective view of a dissolvable proximal capsule of adelivery system according to the present invention;

FIG. 9 is a perspective view of a dissolvable distal capsule of thedelivery system according to the present invention;

FIG. 10A is a partial cross-sectional view of the bypass device and thedelivery system according to the present invention;

FIG. 10B is a cross-sectional view of a portion of the bypass devicewith fluid tubes of the delivery system still coupled thereto;

FIG. 11 illustrates the insertion of a gastroscope and guidewire throughan esophagus of a patient;

FIG. 12 illustrates the bypass device and a portion of the deliverysystem inserted into the stomach in the esophagus of the patient;

FIG. 13 illustrates the deployment of the duodenal anchor and the sleeveinto the duodenum of the patient;

FIG. 14 illustrates the inflation of the gastric and duodenal anchors;

FIG. 15 illustrates the deployment of the sleeve into the smallintestines of the patient;

FIG. 16 illustrates the bypass device in place in its operativeconfiguration in the patient;

FIG. 17 is a partial cross-sectional view of an alternative embodimentof a valve for the duodenal and gastric anchors of the bypass device;

FIG. 18 illustrates an alternative introducer tube for the deliverysystem of the present invention;

FIG. 19 is a perspective view of an obesity device in an operativeconfiguration according to one embodiment of the present invention;

FIG. 20 is a close-up perspective of a proximal portion of the obesitydevice of FIG. 19;

FIG. 21 is a partial cut-a-way top view of a flow restrictor of theobesity device of FIG. 19;

FIG. 22 is a cross-sectional view of an alternative embodiment of a flowrestrictor according to the present invention;

FIG. 23 is perspective view of an interior portion of the flowrestrictor of FIG. 22;

FIG. 24 is a perspective view of an alternative embodiment of a flowrestrictor having multiple projections to form a fan-blade shape;

FIG. 25 is a perspective view of an anchor and a sleeve of the obesitydevice of FIG. 19;

FIG. 26 is a top perspective view of the anchor of FIG. 25;

FIG. 27 is a partial cross-sectional view of another alternativeembodiment of the flow restrictor according to the present invention;

FIG. 28 is a perspective view of a plunger of the flow restrictor ofFIG. 27;

FIG. 29 is a cross-sectional view of yet another alternative embodimentof the obesity device of the present invention;

FIG. 30 is cross-sectional top view of a flow restrictor of the obesitydevice of FIG. 29;

FIG. 31 is a cross-sectional view of another alternative embodiment of aflow restrictor for the obesity device of the present invention;

FIG. 32 is a top view of the flow restrictor of FIG. 31;

FIG. 33 illustrates the insertion of a gastroscope and guidewire throughan esophagus of a patient;

FIG. 34 illustrates the obesity device inserted into the stomach throughan overtube in the esophagus of the patient;

FIG. 35 illustrates the deployment of the anchor and the sleeve ofobesity device into the small intestine of the patient;

FIG. 36 illustrates the obesity device in place in its operativeconfiguration in the patient;

FIG. 37 illustrates the deflation of the flow restrictor in a step inthe removal of the obesity device according to the present invention;

FIG. 38 illustrates the removal of the flow restrictor from the patient;and

FIG. 39 illustrates the deflation of the anchor and removal of theremaining portions of the obesity device from the patient.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the present invention, systems, devices and methods are disclosed fortreating and controlling obesity and/or type II diabetes. In particular,the systems and methods of the present invention provide an internalbypass of a proximal portion of the small intestines to inhibit contactbetween chyme and the bypassed small intestinal walls while allowingnatural peristalsis to occur. The present invention is related toco-pending patent application Nos. 61/123,472 filed Apr. 9, 2008;61/206,048 filed Jan. 27, 2009; Ser. No. 12/420,219 filed Apr. 8, 2009;Ser. No. 12/384,889 filed Apr. 9, 2009; Ser. No. 12/384,890 filed Apr.9, 2009 and Ser. No. 12/384,898 filed Apr. 9, 2009, the full disclosuresof which were previously incorporated herein by reference.

Diabetic foot ulcers are one of the major complications of diabetesmellitus. Foot ulcers occur in 15% of all patients with diabetes andprecede 84% of all lower leg amputations. The significant increase inmortality among diabetic patients with foot ulcers observed over thepast 20 years is considered to be due to the development of macro andmicro vascular complications, including failure of the wound healingprocess.

Wound healing is a ‘make-up’ phenomenon for the portion of tissue thatgets destroyed in any open or closed injury to the skin. Being a naturalphenomenon, wound healing is usually taken care of by the body's innatemechanism of action that works reliably most of the time. The keyfeature of wound healing is the stepwise repair of lost extracellularmatrix (ECM) that forms the largest component of the dermal skin layer.Therefore, controlled and accurate rebuilding becomes essential to avoidunder or over healing that may lead to various abnormalities. But insome cases, certain disorders or physiological insults disturb the woundhealing process that otherwise proceed smoothly in an orderly manner.Diabetes mellitus is one such metabolic disorder that impedes the normalsteps of wound healing process. Many histopathological studies show aprolonged inflammatory phase in diabetic wounds, which causes a delay inthe formation of mature granulation tissue and a parallel reduction inwound tensile strength.

High blood sugar levels prevent white blood cells, which are importantin defending the body against bacteria and also in cleaning up deadtissue and cells, from functioning normally. When these cells do notfunction properly, wounds take much longer to heal and become infectedmore frequently. Also, long-standing diabetes is associated withthickening of blood vessels, which prevents good circulation includingthe delivery of enough oxygen and other nutrients to body tissues.

Another consequence of high blood sugar levels is that the body hasdifficulty producing many important components in the healing process,such as vascular endothelial growth factors (VEGF) and nitric oxide. Forexample, nitric oxide is known as an important stimulator of cellproliferation, maturation and differentiation. Thus, nitric oxideincreases fibroblast proliferation and thereby collagen production inwound healing. Also, L-arginine and nitric oxide are required for propercross linking of collagen fibers, via proline, to minimize scarring andmaximize the tensile strength of healed tissue. Endothelial cellspecific nitric oxide synthase (EcNOS) is activated by the pulsatileflow of blood through vessels. Nitric oxide produced by EcNOS, maintainsthe diameter of blood vessels and proper blood flow to tissues. Inaddition to this, nitric oxide also regulates angiogenesis, which playsa major role in wound healing.

Diabetic patients exhibit reduced ability to generate nitric oxide fromL-arginine. Reasons that have been postulated in the literature includeaccumulation of nitric oxide synthase inhibitor due to high glucoseassociated kidney dysfunction and reduced production of nitric oxidesynthase due to ketoacidosis observed in diabetic patients and pHdependent nature of nitric oxide synthase.

The present invention provides systems, apparatus and methods fortreating wounds in patients, particularly chronic lower limb wounds inpatients lacking the innate ability to regulate glucose (e.g., diabeticpatients). In one aspect of the invention, a method for treating woundsincludes positioning a flexible sleeve within the patient such that thesleeve extends through at least a portion of the duodenum to inhibitcontact between chyme passing therethrough and at least a portion of aninner surface of the duodenum. The hollow sleeve is maintained withinthe duodenum for a sufficient period of time to reduce a blood glucoselevel in the patient. Preferably, the sleeve will be maintained inposition for a sufficient period of time to permit the normalization ofblood glucose levels in the patient (i.e., reducing such glucose levelsto below about 150 mg, preferably below about 125 mg).

The sleeve creates an “internal bypass” that substantially inhibitscontact between chyme and other substances entering the duodenum fromthe stomach of the patient and the bypassed portion of the duodenum.This reduces hormonal triggers that help to down-regulate the productionof glucose, thereby resulting in the relief of certain symptoms thatinhibit the body from effectively healing the wound, such as decreasedperipheral vascular perfusion, neuropathy, a compromised or “inactive”immune system and a reduction in important components of healing, suchas nitric oxide, vascular endothelial growth factors and the like.

In certain embodiments, the sleeve will be maintained in position for asufficient period of time to increase the peripheral vascular perfusionin the patient. Patients lacking the innate ability to regulate glucoselevels often suffer from decreased arterial perfusion of theextremities. The lack of blood flow to the extremities inhibits healingof wounds, such as foot ulcers and the like. In one embodiment of thepresent invention, the flexible sleeve is held in position within theduodenum until this process begins to reverse, thereby increasingperipheral vascular perfusion and allowing for accelerated healing ofthe wound.

In other embodiments, the sleeve will be maintained in position for asufficient period of time to elevate an immune system response in thepatient. Abnormally high glucose levels cause the body's immune systemto become compromised or less active than normal. The white blood cellsor leukocytes of the immune system that defend the body againstinfection become sluggish and unable to effectively fight infections,such as those associated with wounds. In this embodiment, the flexiblesleeve is held in position within the duodenum until the activity ofcirculating leukocytes begins to substantially increase, which allowsthe patient's immune system to do its natural job of fighting theinfection and accelerate healing of the wound.

In other embodiments, the flexible sleeve is maintained in position fora sufficient period of time to increase certain healing factors, such asnitric oxide and vascular endothelial growth factors (VEGF) in thepatient. VEGF is an important signaling protein that stimulates thegrowth of new blood vessels, which can be a critical part of theangiogenesis process in wound healing. In one embodiment of the presentinvention, the flexible sleeve is held in position within the duodenumuntil a sufficient amount of VEGF are produced in the patient toaccelerate healing of the wound.

In other embodiments, the flexible sleeve will be maintained in positionfor a sufficient period of time to halt or reverse neuropathy. Diabeticneuropathy is a common complication of patients lacking the innateability to regulate glucose in which nerves are temporarily orpermanently damaged as a result of high blood sugar levels(hyperglycemia). Neuropathy can complicate the wound healing process,particularly in the extremities. In this embodiment, the sleeve is heldin position until nerves that have not been permanently damaged ordestroyed can be repaired by the body to accelerate healing of thewound.

In a preferred embodiment, the flexible sleeve is sized and shaped toextend from the distal opening of the duodenal anchor through at least aportion of the duodenum (i.e., between about 4-12 inches). In someembodiments, the sleeve may extend throughout the duodenum and into aproximal portion of the jejunum of the patient (i.e., between about12-30 inches, preferably about 12-16 inches). The sleeve issubstantially hollow and positioned such that partially digested food,i.e. chyme, moving through the digestive tract passes through theinterior of the sleeve. This inhibits the absorption ofnutrients/calories in the upper segments of the small intestine anddelays mixing of chyme with digestive enzymes such that a quantity offood ingested by the patient will have a smaller caloric value with thesleeve in place. In addition, it is believed that the sleeve inhibitscertain hormonal triggers that would otherwise occur when food passesthrough the duodenum and proximal jejunum; hormonal triggers that causethe body to become insulin resistant and result in type 2 diabetes.

In certain embodiments, the sleeve is removably introduced through anatural orifice in the patient into the small intestines, preferablyendoscopically through the patient's esophagus, stomach and pylorus. Thesleeve can be maintained in position within the duodenum in a variety ofways known to those of skill in the art (e.g., sutures, hooks, barbs,atraumatic anchoring mechanisms and the like), typically for about 2weeks to one year, preferably between about 1 month to 6 months and morepreferably between about 6-12 weeks.

In a preferred embodiment, the sleeve is maintained in position with apair of anchor elements flexibly coupled to each other and the sleeve.In the preferred embodiment, the flexible anchors are endoscopicallyintroduced with the sleeve and positioned on either side of the pylorus.The duodenal anchor element is preferably expanded to a size that willinhibit proximal movement of the duodenal anchor through the pyloricsphincter to ensure that the sleeve remains in the patient's intestines.Likewise, the gastric anchor element is expanded to a size that willinhibit or prevent distal movement through the pyloric sphincter toensure that the device does not pass further into the intestines andcreate a blockage. In a preferred embodiment, the anchor elements areexpanded by delivering a fluid into each anchor element to inflate saidanchors. In other embodiments, the anchor elements may be expandedmechanically or by other suitable means.

Referring to the drawings, wherein like reference numerals refer to likeelements, there is shown in FIG. 1 an example of a portion of a GI tract10 of a human body. Two smooth muscle valves, or sphincters, contain thecontents of the stomach within the stomach upon ingestion. They are theesophageal sphincter (not shown), found in the cardiac region above theantrum cardiacum, and the pyloric sphincter 20, disposed between thestomach 30 and the small intestine 40. The pylorus 20 is the region ofthe stomach 30 that connects to the duodenum 50. The pylorus 20 isdivided into two parts: the pyloric antrum 60 which connects the body tothe stomach and the pyloric canal which connects to the duodenum 50. Thepyloric sphincter 20 is a strong ring of smooth muscle at the end of thepyloric canal that functions to help regulate the passage of chyme fromstomach 30 to the duodenum 50.

Satiety receptors 80 are generally located all along the inside liningof stomach tissue. Partially undigested food in GI tract 10 is generallyreferred to as chyme. If chyme remains in the region of the stomachbefore flowing into small intestine 40, satiety receptors 80 have agreater chance of being activated, which enhances the ability of anoverweight or obese patient to feel satiated and suppresses the desireto eat.

Pyloric antrum 60 and duodenum 50 are innervated by the enteric nervoussystem and the parasympathetic nervous system (i.e., the vagus nerve).Many researchers have shown that the vagus nerve is responsible for themajority of afferent signals responsible for satiety. Thus, it isbelieved that increasing the afferent vagal nerve activity will resultin satiety signals produced by the brain, making the patient feel morefull and less inclined to eat.

A bypass device according to any of the below-described embodiments ispreferably comprised of a polymeric structure that is compliant andgenerally flexible and bendable. Preferably, at least a portion of thedevice is made of silicone. Some portions of the device may be thickerthan others for enhanced strength properties and to enhance thecapability of the device to resist the natural peristaltic action of GItract 10. Alternatively, some portions of the device may be thinner thanothers to allow for the material peristaltic actions of GI tract 10 tooccur without the device providing a counteractive force. Preferably, ifa portion of the device is bent or twisted during insertion, itspolymeric structure will allow it to revert back to its resting orinitial shape.

The one or more materials that comprise a bypass device according to thepresent invention are preferably selected for their ability to yield andflex during implantation and removal of the device. These propertiesalso protect the patient and the tissues and organs with which thedevice comes into contact. The compliant nature of the bypass deviceallows its configuration to be manipulated during a surgical procedure,preferably in such a way that the device tends to revert to itsoperative configuration. The device may be made of shape memorymaterial, such as nitinol or other known pliable polymeric materials, toallow for expansion back into its operative configuration. Any or all ofthe device may be coated with Teflon to provide a smooth outer surfaceto reduce friction between the device and the patient duringimplantation and removal.

The bypass device according to the present invention is structured toinhibit the rate that chyme passes through GI tract 10, therebyenhancing the ability of chyme to activate satiety receptors 80 andeffectively enhance satiety in a patient. In particular, the device ispreferably structured to reduce the rate of gastric emptying such thatobesity can be controlled by controlling satiety.

The bypass device of the present invention is also designed to provideperiodic or continuous contact pressure on the pyloric antrum and or theproximal portion of the duodenum. This contact pressure modulates(preferably stimulates) one or more nerves within these two structures,thereby increasing their activity. In certain embodiments, this contactpressure is brought about by the design of the device; namely, the flowrestrictor and anchor are coupled to each other by flexible elements orcolumns (discussed in detail below). These flexible columns are sizedsuch that the anchor generally rests against the proximal portion of theduodenum and the flow restrictor generally rests against the distalportion of the pyloric antrum. The flexible columns also have enough“give” or flexibility to allow the anchor and flow restrictor to moveback and forth with the peristaltic motion of the GI tract. Thus, theanchor and flow restrictor may periodically move away from the proximalportion of the duodenum and the distal portion of the pyloric antrum,respectively. However, they will generally move back in contact withthese structures to provide at least periodic pressure contact on thesestructures to stimulate the vagus nerves therein.

The bypass device is also designed to inhibit contact between chymepassing through the duodenum and the inner walls of the duodenum. Thisinhibits the absorption of nutrients/calories in the upper segments ofthe small intestine and delays mixing of chyme with digestive enzymessuch that a quantity of food ingested by the patient will have a smallercaloric value with the sleeve in place. In addition, this reduceshormonal triggers that may help to down-regulate the production ofglucose, thereby resulting in a nearly immediate relief of Type-IIdiabetes symptoms. The stabilization or elimination of Type-II diabetessymptoms will have a beneficial impact on patient health and furtherincrease weight loss.

Incretins are gastrointestinal hormones, produced in response to thetransit of nutrients that boost insulin production. Because an excess ofinsulin can determine hypoglycemia (extremely low levels of bloodsugar)—a life-threatening condition, it has been speculated that thebody has a counter-regulatory mechanism (or “anti-incretin” mechanism),activated by the same passage of nutrients through the upper intestine.The latter mechanism would act to decrease both the secretion and theaction of insulin. Thus, in healthy patients, a correct balance betweenincretin and anti-incretin factors maintains normal excursions of sugarlevels in the bloodstream. In some individuals, however, the duodenumand jejunum may be producing too much of this anti-incretin, therebyreducing insulin secretion and blocking the action of insulin,ultimately resulting in Type 2 diabetes.

Indeed, in Type 2 diabetes, cells are resistant to the action of insulin(“insulin resistance”), while the pancreas is unable to produce enoughinsulin to overcome the resistance. After gastrointestinal bypassprocedures, the exclusion of the upper small intestine from the transitof nutrients may offset the abnormal production of anti-incretin,thereby resulting in remission of diabetes. However, it should be notedthat the scientific community has not settled on a particular mechanismof action that causes patients undergoing such bypass procedures to moreless “insulin resistant”. Thus, the present invention is not limited tothis particular mechanism of action or any particular mechanism ofaction.

Certain components of the bypass device according to the presentinvention may be discussed as being attached or connected to oneanother. Preferably, the device is constructed of one continuous pieceand of one material, preferably silicone. However, two or morecomponents of the device may be manufactured separately and subsequentlyassembled. If assembled, components may be glued together using asilicone-based glue.

FIG. 2 illustrates one preferred embodiment of a bypass device 100according to the present invention. As shown, device 100 includes agastric anchor 102 coupled to a duodenal anchor 104 by a plurality offlexible silicone tethers or pyloric columns 106 and a hollow sleeve 108coupled to the distal end of duodenal anchor 104. Pyloric columns 106are designed to extend through the pyloric sphincter 20 to allow bothgastric anchor 102 and duodenal anchor 104 to have some limited movementback and forth within the stomach 30 and duodenum 50, respectively, withthe natural peristalsis motion of the GI tract (see FIG. 16). Pyloriccolumns 106 may be cylindrical or any other type of prismic shape andare preferably designed such that the distance between the distal end ofgastric anchor 102 and the proximal end of duodenal anchor 104 is about10-60 mm, preferably about 20-40 mm, and more preferably about 30 mm, inthe fully extended, but relaxed condition (i.e., non-elasticallyextended). Preferably, device 100 includes at least two, preferablythree, pyloric columns 106 each having a diameter of about 1-5 mm whichare attached to the inside surfaces of anchors 102, 104. Alternatively,anchors 102, 104 may be coupled together with a hollow sleeve thatextends through the pyloric sphincter 20. The sleeve would preferably besufficiently flexible to allow sphincter 20 to open and substantiallyclose without hindrance from the sleeve.

FIG. 3 illustrates a cross-sectional perspective view of an exemplaryembodiment of gastric anchor 102. As shown, gastric anchor 102 includesan internal ring 110 coupled to an annular inflatable membrane 112having a substantially annular or toroidal shape. Inflatable membrane112 comprises an outer wall 114 surrounding a hollow interior 116configured for inflation via a suitable fluid. Ring 110 and membrane 112preferably comprise a flexible biocompatible material, such as aphosphlipid resistant silicone material (e.g., a fluorosiliconecopolymer). Alternatively, ring 110 may comprise a water-absorbentmaterial, such as a hydrogel, that expands and hardens upon contact withfluid. Ring 110 provides structural support for anchor 102, whileinflatable member 112 allows anchor 102 to move between a collapsedconfiguration for introduction through the patient's esophagus and anexpanded configuration within the stomach. Thus, ring 110 is preferablyharder and less flexible than inflatable membrane 112 having a durometerof at least about 70 A, preferably greater than about 80 A, whilemembrane 112 preferably has a durometer between about 30-60 A, morepreferably between about 40-60 A.

In an alternative embodiment, anchor 102 may simply include aninflatable member 112 without support ring 112. In this embodiment, theinflatable member 112 would be inflated to a size and pressuresufficient to withstand peristalsis forces without compressing to a sizethat would allow the anchor 102 to pass through pyloric sphincter 20.

Gastric anchor 102 further includes a fluid inlet 120 for delivery of afluid into hollow interior 116 of membrane 112. In the preferredembodiment, fluid inlet 120 comprises a valve 122 formed along the innercircumference of ring 110 and extending into interior 116 of membrane.As shown, valve 122 includes small chamber 124 in which a hole 126 isformed. Hole 126 extends radially from the inner surface of ring 110,through ring 110, into interior 116 of membrane 112. A flexible siliconeflap 128, formed as part of the interior surface of the inflatablemember 112, is located adjacent to hole 126. Silicone flap 128 serves toocclude hole 126 once the pressure within interior 116 of inflatablemember 112 exceeds the pressure exterior to the member 112, therebyforming a one-way valve to prevent fluid egress from membrane 112.

In addition to, or as an alternative to, the one-way valve, a curablefluid, such as silicone, may be injected into the fluid pathway afterthe saline. The curable fluid will cure and harden, thereby preventingany fluid egress from the interior of inflatable member 112. In anotherembodiment, the inflatable members of the anchors may comprise amaterial that self-seals when punctured with a very sharp smallinstrument such as a syringe. In this embodiment, the inflatable membersof the bypass device may simply be inflated with a syringe and thenself-sealed by the material to prevent fluid egress.

In the preferred embodiment, ring 110 has an inner diameter of about10-50 mm, preferably about 20-40 mm, and more preferably about 30 mm,and a thickness of about 1-5 mm, preferably about 3 mm. Inflatablemembrane 112 has an outer diameter of about 30-70 mm, preferably about40-50, and more preferably about 45 mm, when the pressure withinmembrane 112 is equal to the pressure outside (the state of nominalinflation, i.e., complete inflation without elastic deformation). In thepreferred embodiment, however, membrane 112 is designed such that fluidcan be injected into interior 116 until it has expanded significantlybeyond the initiation of elastic deformation, with a maximum exteriordiameter of the implanted gastric portion preferably being between about50 and 60 mm.

Duodenal anchor 104 preferably has a similar structure as gastric anchor102; including an inner ring 130 and an annular inflatable membrane 132having a substantially annular or toroidal shape (see FIG. 2).Inflatable membrane 132 is designed to inflate into a substantiallyannular shape that provides for a secure anchor against the distalopening of the pyloric sphincter. This ensures that anchor 104 willremain in place within the duodenum 50 despite the natural peristalsisforces acting against anchor 104. Anchor 104 further includes a valvestructure 134 (similar in design to gastric anchor 102) for delivering afluid into an interior of membrane 132 to inflate membrane 132. In theexemplary embodiment, ring 130 has an inner diameter of between about10-20 mm, preferably about 15 mm, a thickness of between about 1-5 mm,preferably about 3 mm. Inflatable membrane 132 preferably has an outerdiameter of between about 20-30 mm, preferably about 25 mm, when thepressure within membrane 132 is equal to the pressure outside (the stateof nominal inflation, i.e., complete inflation without elasticdeformation). Similar to the gastric component, membrane 132 is designedfor inflation beyond the initiation of elastic deformation, with amaximum exterior diameter of the implanted duodenal anchor being betweenabout 30 and 50 mm, preferably between about 35 to 40 mm.

In an alternative embodiment, gastric and duodenal anchors 102, 104include one or more expandable components that either completely orpartially replace the fluid used in the previous embodiment to inflateor expand anchors 102, 104. In a preferred embodiment, the expandablecomponents comprise fluid-absorbent materials designed to expand uponcontact with certain fluid, such as hydrogels. Hydrogels are networks ofpolymer chains that are water-insoluble and hydrophilic. In thisembodiment, a plurality of hydrogel components (not shown) are housedwithin the inflatable members of anchors 102, 104. The hydrogelcomponents will be introduced into the patient in the “dry” or smallerstate within anchors 102, 104. A fluid, such as saline, is deliveredinto the interior of the inflatable members and is absorbed within thehydrogel components (which may be of any shape, such as spheres or thelike) to expand these components, thereby expanding the inflatablemembers.

In one aspect of this embodiment, the anchors 102, 104 include aplurality of hydrogel beads, preferably about 0.5 to 3.0 mm in diameter,designed to expand to a larger size (e.g., about 4-6 mm in diameter)upon hydration with a fluid, such as saline. In this embodiment, anchors102, 104 may or may not include inner rings 110 and they may not requireone-way valves. The hydrogel balls provide additional rigidity to theanchors 102, 104. In addition, they provide additional safety in theevent that the inflatable members are punctured with a small hole as theballs will remain within inflatable members in such event (as opposed toa puncture that will allow all of the fluid to exit inflatable membersin the previous embodiments). Upon removal of the device, the inflatablemembers will be punctured with a large enough hole to allow the hydrogelballs to exit the interiors of the inflatable members. The hydrogelballs can be allowed to pass through the patient's GI tract and excretednaturally.

FIG. 4 illustrates an alternative embodiment of gastric anchor 102. Inthis embodiment, anchor 102 is substantially similar in design andconstruction as the anchor shown in FIG. 2, comprising a central supportring 110 surrounded by an inflatable member 112 having an internal valve120. However, this anchor 102 also includes an internal restrictor plate150 attached to support ring 110. Plate 150 has a central hole 151designed to allow chyme to pass therethrough. Plate 150 serves tosubstantially inhibit the flow of chyme from the stomach to the pyloricsphincter. It is believed that this will cause the prolongation ofsatiety, and result in fewer meals being eaten and/or smaller mealsbeing ingested. The inner diameter of hole 151 will vary depending onthe rate of chyme flow desired for the individual patient. For example,hole 151 may have a diameter of about 5-20 mm.

Referring to FIG. 5, sleeve 108 may be manufactured to any lengthaccording to a particular patient and/or surgical procedure, and in thepreferred embodiment includes at its distal end a beveled tip 109. Alongits length, sleeve 108 may have one or more side holes 113 which providefurther access for chyme to enter sleeve 108. In some embodiments, a rib131 is disposed along sleeve 108 and is preferably substantiallyparallel to the longitudinal axis of sleeve 108, though rib 131 mayextend only partially along sleeve 108 and may take on a curved or othertype of orientation with respect to the longitudinal axis. Rib 131 maybe comprised of silicone and additionally may include a radiopaquematerial, such as barium, so that rib 131 may be detected by afluoroscope. Rib 131 may be provided as a separate component and laterattached to sleeve 108, or rib 131 may essentially be the overlappingseam formed during the manufacture of sleeve 108 when a flat piece ofmaterial is rolled into a tubular shape. In such a configuration, sleeve108 may be comprised of a homogenous material attached by a radiopaqueglue. Of course, as rib 131 is primarily used as an aid duringimplantation and/or removal of obesity device 100, rib 131 need notnecessarily be included in this or any other embodiment according to thepresent invention.

Sleeve 108 preferably has a diameter that will substantially correspondwith the inner diameter of the patient's duodenum and a length that willallow the sleeve to extend into at least the proximal portion of thejejunum depending on the individual patient's anatomy. Thus, sleeve 108will typically have a length of between about 20-80 cm, preferablybetween about 55-75 cm, a thickness of about 0.05 mm to 0.22 mm and adiameter of between about 1 to 3 cm, preferably about 2.5 cm.Preferably, the proximal portion of sleeve 108 has an inner diameter ofabout 1.2 cm that expands laterally in the proximal direction to 1.5 cmso that it may be sealed to the lower surface of anchor 104. Thematerial of the sleeve is preferably silicone, such as apolyethylene-reinforced silicone.

Sleeve 108 may include one or more markers (e.g., barium) designed forviewing the position of the sleeve within the intestines throughfluoroscopy, such as rib 131 or other markers that are spaced along thelength of sleeve 108. In addition, sleeve 108 may further includecomponents that inhibit twisting or kinking of the sleeve 108. In oneembodiment, these components include one or more stiffening elements,such as rings, coupled to either the inside or the outside of the sleeveat spaced locations along its length. These rings can, for example, bemade of a slightly thicker silicone material that would resist twistingor kinking of the sleeve around the ring. In other embodiments, thestiffening elements may be in spiral shape or extending lengthwise alongat least a portion of the sleeve 108.

Sleeve 108 may also include one or more internal lumens extending alonga portion of or the entire length of the sleeve. The fluid lumenscomprise a proximal end configured for coupled to a fluid deliverysystem to allow a fluid to flow through sleeve to extend sleeve throughthe patient's duodenum and/or to ensure that sleeve remains patentwithout any twists or kinks along its length. In one embodiment, thesleeve comprises multiple (e.g., 2-5) internal lumens extending from theproximal to the distal end of the sleeve and spaced from each otheraround the circumference of the sleeve. In another embodiment, thesleeve comprises an internal lumen that extends in a spiral pattern downthe length of the sleeve.

In yet another alternative embodiment, sleeve 108 may further includeone or more fluid chamber(s) coupled to one or more of the internallumens. The fluid chamber(s) facilitate implantation of the sleevewithin the patient by allowing the physician to at least partially fillone or more of the chambers before withdrawing the scope from theduodenum (discussed in more detail below). In addition, the fluidchambers provide stiffness to the sleeve to provide more stability tothe sleeve and ensure that it remains in place within the patient afterimplantation. The fluid may also include a material that is observableunder fluoroscopy (e.g., barium or the like) such that the location ofthe internal lumens and/or the fluid chambers can be viewed by aphysician after implantation.

In one embodiment, the fluid chamber comprises an annular passageextending around the circumference of the sleeve at or near its distalend. This configuration provides the additional advantage that, whenfilled, the annular fluid chamber provides a distal anchor for thesleeve and the entire bypass device to provide additional againstproximal migration of the sleeve and/or device. In another embodiment,the sleeve comprises multiple annular fluid chambers spaced along thelength of the sleeve to provide additional rigidity to the sleeve,thereby ensuring that the sleeve remains patent and preventing anykinking or twisting along its length.

In an alternative implantation method, the sleeve 108 may be initiallyfolded “accordion-style” and tucked into the interior of the anchor 104.The distal end of sleeve 108 is initially closed, with a small siliconerubber knob (not shown) attached to the bottom of sleeve 108 (e.g., likea “sock” with a ball on the inside surface of the “toe”). Just proximalto the ball, at a region where the diameter of sleeve 108 is about 2.1cm, is a circumferential perforation (not shown) such that the ball andthe “toe portion” of the sleeve will tear away from sleeve 108 leavingan open tubular sleeve behind.

Referring now to FIGS. 6 and 7, an alternative embodiment of a duodenalanchor 230 will now be described. As shown, anchor 230 comprises anannular support ring 240 coupled to an inflatable flexible membrane 242.In this embodiment, support ring 240 comprises two flat ring elements244 connected together by a semi-rigid central ring 246 that holds theflat ring elements 244 apart from each other. Flat ring elements 244 andcentral ring 246 preferably comprise a suitable material, such assilicone, which may be molded as one-piece or molded separated and gluedtogether with a suitable silicone glue. Flat ring elements 244 arepreferably separated from one another by a distance of about 8-12 mm.Flexible membrane 242 is sealed to the exterior circumferential surfacesof flat ring elements 244 and central ring 246. Membrane 242 isinitially tucked in a space 250 between flat ring elements 244 withsufficient additional material such that when saline is injected intothe interior of membrane 242, an inflated “inner tube” structure iscreated. This inner tube structure is intended to inflate to a maximumdiameter of between 30-45 mm (depending on the specific duodenal anatomyof a given patient).

A one-way valve 252 is disposed between ring elements 244 at onelocation around the circumference thereof and directed inwardly. Thisvalve 252 is initially coupled to a thin tube (not shown) that extendsup along the exterior of the gastric anchor through which membrane 242can be inflated. In an exemplary embodiment, a small wire (not shown) isincorporated into the seal of the inner membrane 242 to the rings topermit simple and rapid deflation of membrane 242 for removal of thedevice. A small ball (not shown) may also be coupled to the wire andlocated external to ring elements 244 and membrane 242 for grasping byan endoscopic instrument. Pulling the ball causes the wire to tearthrough membrane 242 and the seal, thus rupturing membrane 242 andcollapsing anchor 230.

Referring now to FIGS. 8-10B, bypass device 100 further comprises adeployment system 200 for facilitating the deployment of device 100. Asshown in FIGS. 8 and 9, deployment system 200 includes a proximalhousing or capsule 202 and a distal housing or capsule 204. Capsules202, 204 both comprise a biocompatible dissolvable material, such asgelatin and the like, designed to dissolve within the patient's body. Asshown in FIG. 8, distal capsule 204 is sized and shaped to house sleeve108 in a folded, compressed or collapsed configuration and duodenalanchor 104 in its collapsed or deflated configuration (see FIG. 10A).Distal capsule 204 is open at its proximal end, and has a bullet-shapeddistal tip 208 with a small hole 206. Distal tip 208 is designed tofacilitate passage of the capsule 202 (and sleeve 108 and anchor 104therein) through the pylorus and into the duodenum. Hole 206 is sizedand shaped for passage of a guidewire therethrough (see FIGS. 11-15).Capsule 202 is preferably about 80-160 mm long (preferably about 100-140mm long) about 10-30 mm wide (preferably about 20 mm) and is preferablyconstructed to survive for less than 30 minutes before dissolving in thehuman intestines.

As shown in FIG. 9, proximal capsule 202 is sized and shaped to housegastric anchor 102 in its collapsed configuration and at least a portionof columns 106 therein (see FIG. 10A). Proximal capsule 202 issubstantially cylindrically shaped and is primarily designed tofacilitate passage of these components through the esophagus to minimizeany damage to the inner walls of the esophagus. To that end, capsule 204has a slightly curved distal end 205 with an opening 207 that is largerthan distal opening 206 of distal capsule 204 to accommodate the variouscomponents of bypass device 100 therethrough, such as flexible columns106; delivery structure 150 and fluid tube 210 (see FIG. 10B). In thepreferred embodiment, capsule 202 is about 30-70 mm long (preferablyabout 50 mm) and about 10-30 mm wide (preferably about 20 mm). Capsule202 preferably comprises a material that will dissolve in less than 15minutes within the human stomach, such as gelatin and the like.Alternatively, capsules 202, 204 may comprise a resorbable material or amaterial that can be safely excreted by the patient.

Referring now to FIGS. 10A and 10B, deployment system 200 furtherincludes fluid tubes 210, 212 coupled to valves 122, 134 of gastric andduodenal anchors, respectively. Tubes 210, 212 each include smallone-way valves (not shown), such as an umbrella valve or a duckbillvalve, formed in their distal tips. Tubes 210, 212 are preferablycoupled to valves 122, 134 such that their own own-way valves are formedwithin the small chambers 124 of valves 122, 134. Upon inflation of therespective components, the tubes 210, 212 are then cut proximal tovalves 122, 134 such that their one-way valves provide additionalprotection to ensure that fluid injected into the inflatable membranes112, 132 cannot escape through the holes.

Deployment system 200 further comprises a central tube structure 150designed to extend through bypass device 100 (i.e., through the centerof gastric and duodenal anchors 102, 104 and sleeve 108). Central tubestructure 150 has a support tube 152 with an inner lumen (not shown)sized for passage of a guidewire therethrough (discussed in detailbelow). Support tube 152 has an inner diameter of at least 2.8 mm andpreferably about 3 mm. Support tube 152 extends through hole 206 indistal capsule 204 and preferably has widened distal tip 155 designed toengage the outer surface of distal tip 208 of capsule 204. Thisfacilitates passing of guidewire into the distal opening of support tube152. Alternatively, support tube 152 may comprise an enlarged distal end(not shown) having a larger diameter than hole 206 that is locatedwithin capsule 204. In this embodiment, the enlarged distal end ofsupport tube 152 operates to push against capsule to propel capsule 204forward as it advances through the patient's GI tract. Support tube 152preferably comprises a material that has sufficient flexibility toeasily navigate the patient's small intestines, yet sufficient rigidityto allow for a pushing force from outside of the patient's body toadvance tube 152 and the rest of bypass device 100 through the patient'sGI tract (discussed below). Suitable materials for support tube 152 arepolypropylene and the like.

Central tube structure 150 further comprises a flexible tube 154extending alongside support tube 150. Flexible tube 154 houses a wire156 coupled to a snare or a clamp 158 at its distal end. An actuator,such as a handle 160 (see FIG. 12), is coupled to the proximal end ofwire 156 for opening and closing clamp 158. As discussed below, flexibletube 154 and clamp 158 are designed to facilitate advancement of sleeve108 through the patient's small intestines to its final deploymentposition. Note that flexible tube 154 and support tube 152 mayalternatively comprise a single tubular structure with two separatelumens (one for wire 156 and one to accommodate the guidewire).

In one embodiment, sleeve 108 comprises one or more small extensions orpolyps (not shown) extending from its distal tip. In this embodiment,tube 154 includes a distal tip (not shown) with a clamp or fastenerdesigned to fasten to the polyps to facilitate advancement of sleeve 108as discussed above. When the sleeve is in its final deployment position,an actuator on handle on the proximal end of the tube 154 allows the useto pull the clamp proximally relative to the distal tip to sever thepolyps and thereby detach tube 154 from the sleeve 108. At this point,central tube structure 150 can be removed from the patient. The polypswill then pass through the patient's GI tract in a normal manner.

In an alternative embodiment, deployment system 200 includes a thin,hollow sheath coupled to a silicone ball (not shown). The ball isdetachably coupled to the distal end of sleeve 108 and the sheathextends through sleeve 108 and duodenal and gastric anchors 102, 104.The ball has an axial hole formed therethrough aligned with the axialbore of the sheath. The axial bore of the flexible sheath has a lengthof about 120 mm, and an outer diameter of about 5 mm. The sheath andball together allow the user to advance sleeve 108 through theintestines to its final deployment position.

In reference to FIGS. 11-16, a method of implanting and removing abypass device 100 according to the present invention will now bedescribed. While the description of this method will be specificallydirected to the embodiments illustrated in FIGS. 2 and 3, it will beunderstood by those skilled in the art that this method (or similarmethods) can be used to implant and remove all of the embodiments of thepresent invention, including embodiments or designs that may not bespecifically described or illustrated herein.

Device 100 enters and exits the patient through esophagus 302 and isultimately positioned in its operative state, wherein pyloric columns106 extend through pyloric sphincter 20 (e.g., see FIG. 15). Initially,a gastroscope 306 is lubricated, inserted into patient's mouth 307, andfed through esophagus 302 and the gastroesophageal (“GE”) junction intostomach 30, as shown in FIG. 11. Gastroscope 306 is preferablyapproximately 9.8 millimeters in length, and preferably hasapproximately a 2.8 millimeter working channel and suitable viewing andrecording equipment, for example. It will be understood that tools andcomponents that are described as being passed through or inserted intogastroscope 306 are passed through or inserted into its working channel.A lubricant such as Surgilube or equivalent may be provided as needed tolubricate the bypass device and/or any of the associated surgicalequipment.

Gastroscope 306 should ultimately be positioned such that its distal end308 is adjacent to pyloric sphincter 20. Preferably, a guidewire 322 ishydrated and inserted through gastroscope 306. Guidewire 322 is passedthrough pyloric sphincter 20, which may be aided by manipulation ofgastroscope 306. It may also be beneficial to pass a distal end 308 ofgastroscope 306 through pyloric sphincter 20 in order to maneuverguidewire 322 through same. There should preferably be at least about30-40 centimeters of the length of guidewire 322 passed distally throughpyloric sphincter 20 and into small intestine 40 so that any furthermovement of guidewire 322 during the insertion procedure does not resultin the accidental removal of the distal end of guidewire 322 to aposition proximal of pyloric sphincter 20. Of course, the length ofguidewire 322 that should preferably be passed distally through pyloricsphincter 20 may vary according to different patients and/or proceduresand may be less or more than 30-40 centimeters. After guidewire 322 isappropriately positioned, gastroscope 306 is removed from the patient.

Referring now to FIG. 12, bypass device 100 and delivery system 200 arelubricated and positioned over the guidewire 322 outside of the patientby advancing the proximal end of guidewire 322 through hole 206 indistal capsule 204 and into the inner lumen of support tube 152 (seeFIG. 10A). In some embodiments, an overtube (not shown) may bepositioned over the guidewire 322 and advanced through the esophagus andinto the patient's stomach. The overtube typically has an inner diameterof approximately 16 mm. However, in the preferred embodiment, anovertube is not required for implantation of bypass device 100. A smallsteerable scope (not shown) may be advanced through the esophagus intostomach 30 through the pylorus and into the proximal portion of theduodenum. The scope is used to confirm the tissue of the stomach,pylorus and duodenum are robust and show not overt signs that they willnot tolerate the device. In an exemplary embodiment, a small tube (notshown) may be inserted into the pylorus. The tube includes a distalinner tube-shaped balloon (not shown) that expands to a known diameterwith a known volume of saline. In conjunction with the scope images andother prior imaging data, this instrument is used to determine theappropriate size of bypass device 100 to be used, particularly theappropriate size of duodenal anchor.

Referring now to FIG. 12, once the appropriate size bypass device 100 isselected, distal capsule 204 (containing sleeve 108 and duodenal anchor104) and proximal capsule 202 (containing gastric anchor 102 and atleast a portion of columns 106) are then advanced through the esophagusand into the stomach along guidewire 322. Once through the esophagus,distal and proximal capsules 204, 202 separate, but remain flexiblycoupled together by columns 106 and fluid tube 210 (note that tubes 210,212 are not shown in FIG. 12). The capsules 202, 204 are also stillaligned with each other by virtue of delivery tube structure 150 andguidewire 322 that remain extending through the entire device 100. Oncethe entire device is within the stomach, support tube 152 is used topush the distal end of delivery tube structure 150 and distal capsule204 through the pylorus into the proximal duodenum (see FIG. 13). Thismay require the use of a dilator (not shown) to maintain the pylorus inits maximum diameter. Alternatively, a separate pusher rod (not shown)may be used to push the distal components of bypass device 100 intostomach 30. It should be noted that it may not be necessary toencapsulate any components of device 100 in order to advance themthrough the patient's GI tract. In this case, these components willsimply be advanced in their deflated configurations.

At this point, the surgeon will wait until capsules 202, 204 dissolve(unless capsules 202, 204 are not being used). It is expected thatproximal capsule 202 will dissolve more rapidly, as it is designed to doso, and is subjected to a slightly more caustic environment within thestomach (alternatively, capsules 202, 204 may comprise material that canbe excreted naturally by the patient). Once the proximal components ofbypass device 100 are freed from capsule 202, a fluid, such as saline,is introduced through fluid tube 212 into the interior of inflatablemember 112 until it is filled to the appropriate size (see FIG. 14).After inflating gastric anchor 102, and after distal capsule 204 hasalso dissolved, fluid is delivered through fluid tube 210 into theinterior of inflatable member 132 of duodenal anchor 104 in a similarfashion.

Referring now to FIG. 15, once duodenal anchor 104 has been inflatedinto its operative configuration, sleeve 108 is advanced through theduodenum and into the jejunum to its final deployment position.Specifically, support tube 152 is used to push sleeve 108 and deliverystructure 150 through the patient's small intestines. Once in finalposition, clamp 158 is released via the actuator device or handleoutside of the patient (not shown) to disengage it from the distal endof sleeve 108.

In an alternative embodiment, the surgeon will not wait until distalcapsule 204 is dissolved before advancing sleeve 108 to its finaldeployment position in the small intestines. In this embodiment, oncecapsule 204 has been advanced through the pylorus into the proximalduodenum, gastric anchor 102 is inflated as discussed above. Capsule 204is then advanced further into the duodenum until duodenal anchor 104 isforced out of the proximal opening of capsule 204 (anchor 104 will beprevented from further distal movement by gastric anchor 102). Capsule204 will then be advanced through the duodenum until the distal end ofsleeve 108 reaches its final deployment position. Clamp 158 is thendisengaged from sleeve 108 and removed from the patient as describedabove and capsule 204 will eventually dissolve.

As shown in FIG. 16, bypass device 100 should now be in its finalposition with gastric anchor 102 in pyloric antrum of stomach 30 andduodenal anchor 104 just distal to the pyloric sphincter 20. Deliverystructure 150 is removed from the patient and the distal end of fluidtubes 210, 212 are cut with scissors or the like and removed. Agastroscope and/or fluoroscope (not shown) may be used to confirm thefinal placement of device 100. Once device 100 is in place, guidewire322 can be also removed from the patient.

A method for removing bypass device 100 according to the presentinvention will now be described. A gastroscope may be advanced throughthe esophagus and into the stomach 30 of patient in a suitable positionfor the surgeon to view the procedure. A sharp instrument (not shown)such as scissors or the like, is advanced through the patient'sesophagus into stomach 30. The sharp instrument is used to puncturegastric anchor 102 such that the fluid within the interior of membrane112 exits into the stomach to deflate anchor 102. Alternatively, asyringe or similar suction device (not shown) may be attached to thevalve inlet 120 to withdraw the fluid from gastric anchor 102.

Once deflated, gastric anchor is preferably positioned to the side ofthe antrum. A grasping or cutting instrument (not shown) is advancedthrough the esophagus to cut each of the pyloric columns 106 to detachgastric anchor 102 from the distal portion of device 100. The lastcolumn 106 that is severed will be held by the grasping instrument toensure that duodenal anchor 104 and sleeve 108 do not migrate in thedistal direction after being detached from gastric anchor. At thispoint, a grasping tool or snare (not shown) is advanced into stomach 30to grab gastric anchor 102 and gastric anchor 102 is then pulled throughthe esophagus and removed from the patient.

The sharp cutting instrument is then advanced through the pyloricsphincter 20 to puncture membrane 132 of duodenal anchor 104 to deflateduodenal anchor 104. The grasping instrument may then be used to pullanchor 104 and sleeve 108 into stomach 30. Once duodenal anchor 104 andsleeve 108 are within stomach 30, they may be sliced up and removed orremoved as a single unit. Subsequent to the removal of device 100, ascope (not shown) can be used to determine if any tissue injury orinsult that has been sustained by the implantation, use, or removal ofdevice 100. Provided no additional access to the stomach, pylorus, orduodenum is required, removal of the scope concludes the procedure.

Alternatively, the duodenal anchor 104 can be deflated without severingcolumns 106 and removing gastric anchor 102. In this embodiment, thesharp instrument is advanced around gastric anchor 102, through columns106 and pylorus 20 to duodenal anchor 104. Duodenal anchor is deflatedand pulled into the stomach (along with sleeve 108). The entire bypassdevice 100 may then be removed as a single unit, or it may be sliced upinto smaller components to facilitate passage through the patient'sesophagus.

FIG. 17 illustrates one portion of an alternative embodiment of thegastric and duodenal anchors (for convenience only one of the anchors isshown in FIG. 17). In this embodiment, the anchors both include an outerwall housing a hollow interior designed for inflation as describedabove. FIG. 17 illustrates a central portion 400 of the outer wall ofthe anchors. As shown, the anchors further include a valve 402 having aninlet 404, a one-way valve member 406, a fluid passage 408 and anexpandable member 410 located within fluid passage 408 between theinterior of the anchor and valve member 406. Expandable member 410preferably comprises a material designed to slowly absorb fluid upon,such as water or saline and expand with the absorbed fluid. In thepreferred embodiment, expandable member 410 comprises a hydrogelmaterial although other materials can be used that are well known in theart.

To inflate the anchor, fluid is delivered through inlet 404 such that itpasses via fluid passage 408 past expandable member 410 and valve member406 into the interior of the anchor. Valve member 406 is designed toprevent the fluid from flowing back through fluid passage 408 and inlet404. As additional protection from this event occurring, however,expandable member 410 will absorb fluid as the fluid fills the interiorof the anchor and passes back through passage 408 to saturate expandablemember 410. Expandable member 410 is designed to expand when hydratedsuch that it completely blocks fluid passage 408, thereby preventing anyfluid flow in either direction through fluid passage. This not onlyprovides additional protection from fluid leakage, but also prevents anyunwanted fluid (such as stomach acid and the like) from passing into theinterior of the anchor.

FIG. 18 illustrates an alternative embodiment of a delivery system 450of the present invention. In this embodiment, system 450 comprises anintroducer tube 451 defining an elongate shaft 452 that has sufficientflexibility to extend through a patient's esophagus into the stomach(similar to the overtube described above). Shaft 452 has an open distalend 454 and an open proximal end (not shown as the entire shaft 452 oftube 451 is not shown in FIG. 18) and an internal lumen 458 designed asa working channel for passing instruments therethrough. Tube 451 furthercomprises a thin flexible bag or sleeve 460 comprising a suitablebiocompatible material such as silicone or the like. Sleeve 460 houses abypass device 462 such as one of the bypass devices described above.Sleeve 460 is preferably long enough to extend entirely through internallumen 458 of shaft 452 to facilitate placement of sleeve 460 and device462 in tube 451 (see below). In the preferred embodiment, sleeve 460 hasopen distal and proximal ends and is fastened to the proximal end ofintroducer tube 451 such that sleeve 460 remains within tube 451 whendevice 462 is propelled from tube 451 (see below). Sleeve 460 is alsosized to allow it to fit within internal lumen 458 while still housingbypass device 462 in its collapsed configuration.

System 450 may optionally include a pusher or advancing member 464including an elongate rod 465 with a proximal handle (not shown) and adistal pusher 466 designed to press against a proximal end of bypassdevice 462 when bypass device 462 is loaded within lumen 458 of tube451. In some embodiments, handle (not shown) can be used to collapse orexpand pusher 466 (discussed below). Tube 451 further comprises atapered distal end 459 around distal opening 454 to provide foratraumatic advancement through the esophagus.

In use, bypass device 462 is placed within sleeve 460 and sleeve 460 isloaded into the distal end portion of internal lumen 458. In a preferredembodiment, the user extends the proximal end of sleeve 460 through theentire length of lumen 458 and pulls sleeve 460 proximally such thatbypass device 462 is pulled into the distal end portion of lumen 458.Once loaded, the device 462 is ready for implantation in the patient.

To implant the device, introducer tube 451 is extended through thepatient's esophagus such that its proximal opening 454 is positionedwithin the stomach. Bypass device 462 is then propelled out of tube 451into the stomach. This can be accomplished by passing advancing member464 through proximal opening of introducer tube 451 and advancing itthrough lumen 458 until it propels bypass device 462 out of the distalopening 454 of tube 451. Alternatively, other devices, such as agastroscope, can be used to propel bypass device into the stomach.

In the preferred embodiment, sleeve 460 has open proximal and distalends and is designed to remain within lumen 458 of tube 451 as bypassdevice 462 is advanced into the stomach. Thus, both sleeve 462 and tube451 can be easily removed from the patient after device 462 has beendeployed. In other embodiments, sleeve 462 passes into the stomach alongwith device 462 and is then detached or removed from device 462. Thiscan be accomplished by a variety of means, such as cutting the sleeveaway from the device 462. Alternatively, sleeve 462 may already includea cut-a-way portion that can be easily detached to open sleeve 462 andallow bypass device 462 to be removed. In yet another embodiment, sleeve462 may comprise a dissolvable material that dissolves away within thestomach (similar to the capsules discussed above). Once it has beendeployed into the stomach, bypass device 462 may be passed along aguidewire and deployed into its final position as discussed above.

In certain embodiments, introducer tube 451 is long enough to extendthrough the esophagus and stomach and through the pylorus into theduodenum of the patient. In these embodiments, tube 451 may optionallyinclude a bend at its distal end portion to facilitate passage of thetube 451 through the natural bend in the human stomach between theesophagus and the pylorus. Alternatively, the delivery system mayinclude a separate overtube having such a bend. In this embodiment, theseparate overtube will be first inserted through the esophagus with aseparate straight introducer therein (i.e., to maintain the overtube ina substantially straight configuration as it passes through theesophagus). Once the overtube has passed through the esophagus, thestraight introducer is removed such that the overtube is allowed to bendwithin the stomach into its natural position. At that point, theflexible introducer tube 451 housing the bypass device is advancedthrough the overtube to the duodenum.

In use, once the distal opening of tube 451 resides in the duodenum, thedistal end portions (i.e., the sleeve and the duodenal anchor) of thebypass device are propelled out of the distal opening of the introducertube 451 and into the duodenum of the patient. The duodenal anchor isthen inflated to prevent proximal movement of the distal end portions ofthe bypass device. The introducer tube 451 is then retracted through thepylorus and into the stomach. As this occurs, the gastric anchor willnaturally be pulled out of the distal end of the introducer tube 451from the counterforce of the inflated duodenal anchor against the distalsurface of the pylorus. The gastric anchor may then be inflated withinthe stomach and the sleeve extended through the duodenum as describedabove.

In yet another alternative embodiment, the pusher device or advancingmember is designed to perform multiple functions. Namely, the pusherdevice is sized and shaped to fit between the gastric and duodenalanchors within the introducer tube. In this capacity, the pusher deviceis used to push or propel duodenal anchor and sleeve out of the distalopening of the introducer tube into the duodenum. In addition, thepusher device will function to prevent the gastric anchor from beingadvanced through such distal opening when the distal opening is locatedwithin the duodenum. Once the distal opening of the introducer tube hasbeen retracted through the pylorus into the stomach, the pusher deviceis designed to collapse and retract proximally through the middle of thegastric anchor. It can then be expanded again to propel the gastricanchor through the distal opening of the introducer tube and into thepatient's stomach.

In one embodiment, the pusher device comprises an elongate rod coupledto a umbrella-shaped or claw-shaped proximal pushing device. The rod issized to extend through the introducer tube and through the center ofthe gastric anchor. The proximal pushing device is sized to residebetween the gastric and duodenal anchors. Distal advancement of the rodwill cause the pusher device to propel the duodenal anchor through thedistal opening of the introducer tube. The pusher device furthercomprises an actuator at the proximal end of the rod for collapsing theumbrella-shaped pushing device such that it can be retracted proximallythrough the center of the gastric anchor. The actuator can then be usedto expand the pushing device such that further distal advancement of therod will cause the pusher device to propel the gastric anchor throughthe distal opening in the introducer tube.

In yet another embodiment, an alternative method for implanting andremoving the bypass devices of the present invention is now described.In this embodiment, the hollow sleeve includes one or more projectionsat its distal end designed to allow an endoscopic forceps, clips, clampor similar device to attach to the projections. The projections can beloops, strings, protuberances or the like and are preferably made of thesame material as the sleeve (such as silicone). The gastric and/orduodenal anchors may also include such projections for similar purposes.

In use, the bypass device is attached to an endoscopic scope by passingan endoscopic forceps or clamping device through the working channel ofthe scope and attaching the forceps to the projections on the distal endof the sleeve. The physician may then attach the remainder of the bypassdevice to the outer surface of the scope with a shroud, sleeve or otherfastening device or just simply align the bypass device with the shaftof the scope. Alternatively, the scope may be advanced through thecenter of the two anchors of the bypass device and the sleeve such thatthe entire bypass device is positioned around the scope. The scope isadvanced with the distal end of the sleeve through the patient'sesophagus and stomach and through the pylorus into the duodenum. Theremainder of the sleeve and the anchors of the bypass device are therebypulled into the stomach alongside the scope.

Alternatively, the physician may attach the forceps to the projectionson either the gastric or duodenal anchor and advance those portions ofthe implant through the esophagus first (i.e., passing the device intothe stomach backwards). In this embodiment, the physician may thendetach the forceps from the bypass device, remove the scope and attachthe forceps to the distal end of the sleeve to advance the remainder ofthe sleeve into the patient's stomach. To avoid retraction of theanchors back through the esophagus, the gastric anchor may be fully orpartially inflated after the forceps have been detached from the anchorand before withdrawing the scope through the esophagus.

After the anchors have been advanced into the stomach of the patient,the gastric anchor is preferably either partially or fully inflated asdescribed above to prevent movement of the gastric anchor through thepylorus into the duodenum or through the lower esophageal sphincter intothe esophagus. The physician then continues to advance the scope and thedistal end of the sleeve through the duodenum to a position near thefinal target site within the patient's intestines (either in the distalduodenum or the proximal jejunum). At this point, the physician maydetach the forceps from the distal end of the sleeve and withdraw thescope and forceps back into the patient's stomach.

To prevent the sleeve from “following” the scope proximally into thestomach, the physician will preferably temporarily fixate the sleevewithin the duodenum. According to the present invention, one method oftemporarily fixating the sleeve is to use a detachable clip (rather thanthe forceps described above) to grab the projection on the distal end ofthe sleeve. Once in position within the duodenum, the clip is opened andattached to mucosal tissue within the duodenum. The clip can then bedeployed such that it is no longer attached to its shaft, but insteadfastens the sleeve to the mucosal tissue on the inner wall of theintestines. This allows the scope and shaft of the clip device to bewithdrawn while the sleeve is fixated within the duodenum.

In certain embodiments, multiple clips may be used to fasten the sleeveto the inner walls of the intestines. The clips may serve the purpose ofcreating an additional anchor for the device to prevent migration and toensure that the sleeve remains patent during the period of time it isimplanted within the patient. In addition, the clips will preferably beobservable under fluoroscopy such that the physician can ensure that thesleeve has remained in place after implantation.

In another embodiment, the sleeve comprises one or more internal lumensextending down a portion of, or the entire length of, the sleeve. Theinternal lumens are preferably fluidly coupled to one of the flexiblecolumns which are, in turn, fluidly coupled to a valve within thegastric anchor. In an exemplary embodiment, the sleeve will comprise 3or 4 internal lumens spaced around its circumference. In use, a fluid isdelivered through the gastric anchor and column and into the internallumens of the sleeve. The fluid causes the sleeve to extend fully andinhibits proximal migration of the sleeve when the scope is retractedfrom the patient's duodenum. In addition, the fluid-filled lumens willensure that the sleeve remains patent without any kinks or twists alongits length.

Once the scope has been retracted from the duodenum, the duodenal anchoris advanced past the patient's pylorus into the proximal portion of theduodenum. Preferably, the scope is used to push the duodenal anchorthrough the pylorus. Alternatively, the forceps can be attached to oneof the projections on either of the gastric or duodenal anchors to pushand/or pull the duodenal anchor into position. The duodenal anchor isthen inflated as described above.

In yet another alternative embodiment, the sleeve is “self-deploying”through the duodenum. In this embodiment, the sleeve is positionedwithin the proximal duodenum as described above and then allowed to“self-deploy” and advance through the duodenum into position. In oneembodiment, the sleeve comprises internal fluid lumens as describedabove and the fluid is delivered into the lumens to force the sleeve toextend down the length of the duodenum. In another embodiment, thesleeve comprises a mass at its distal end (e.g., a thickened annularportion of the sleeve, one or more balls or projections attached to thedistal end or the like). The mass will advance through the patient'sintestines through natural peristalsis and pull the sleeve distallyuntil it is fully extended. In yet another embodiment, the sleevecomprises a dissolvable portion at its distal end that occludes all or aportion of the distal end of the sleeve. In this embodiment, fluid isflushed through the sleeve and because its distal end is occluded causesthe sleeve to extend distally. After the dissolvable portion dissolveswithin the intestines, the distal end of the sleeve is opened up toallow chyme to pass therethrough.

FIGS. 19 and 20 illustrate an embodiment of an obesity device 500according to the present invention. As shown, device 500 includes agastric flow restrictor 502 coupled to a duodenal anchor 504 by aplurality of flexible silicone tethers or pyloric columns 506 and ahollow sleeve 508 coupled to the distal end of anchor 504. Pyloriccolumns 506 are designed to extend through the pyloric sphincter 20 toallow both flow restrictor 502 and anchor 504 to move back and forthwithin the stomach 30 and duodenum 50, respectively, with the naturalperistalsis motion of the GI tract (see FIG. 36). Pyloric columns 506may be cylindrical or any other type of prismic shape and are preferablydesigned such that the distance between the distal end of flowrestrictor 510 and the proximal end of anchor 504 is about 30 mm in thefully extended, but relaxed condition. Preferably, device 500 includesthree or more pyloric columns 506, which are attached to the distal endof flow restrictor 502, through a button (not shown). The button ispreferably comprised of a material having a greater rigidity than therest of device 500, and may either be co-molded into device 500 orassembled afterward as a separately manufactured component. The buttonis preferably configured similarly to a conventional button, beingdisc-shaped and having two or more bores (not shown). The button may bedisposed within or adjacent to the distal-most flange. Alternatively,columns 506 may be glued to flow restrictor 502 or coupled to flowrestrictor 502 during the molding process, as described above.

FIG. 21 illustrates one embodiment of gastric flow restrictor 502 in anoperative or expanded configuration. Flow restrictor 502 defines alongitudinal axis 503 and comprises one or more flanges 510 coupled to acentral tube 512 extending substantially parallel to axis 503. Centraltube 512 preferably comprises a moderate durometer siliconeapproximately 20-50 mm in length and about 4-10 mm in outer diameter.Central tube 512 defines a lumen 514 along axis 503 for passage of aguidewire (not shown) during implantation and removal of obesity device500 (discussed in detail below). In some embodiments, lumen 514 willhave a inner diameter sized to also allow a scope (not shown) with aworking channel to pass through. In other embodiments, lumen 514 will besmaller and sized only for passage of a guidewire.

Flow restrictor 502 further comprises one or more discs or flanges 510extending outward from tube 512 and longitudinally spaced from eachother. Flanges 510 may have identical or varying outer diameters, anddue to their composition, may flex and bend during positioning of device500 in stomach 30. Flanges 510 preferably have a thickness of about 1-6mm and comprise a lower durometer silicone than central tube 512. In thepreferred embodiment, obesity device 500 comprises a proximal flangethat is larger in diameter than the distal flanges and effectivelyserves as the proximal surface of the central tube 512. This providesflow restrictor 502 with a shape substantially corresponding to theanatomy of the distal portion of stomach 30. All of the flanges 510 willhave an outer diameter larger than the maximum diameter of the pyloricsphincter 20. The proximal flange preferably has an outer diameter ofabout 40-60 mm, preferably about 50 mm, while the distal flangespreferably have an outer diameter of about 20-40 mm, preferably about 25mm. Flanges 510 may also bend or flex due to the natural peristalticaction of stomach 30 during contact with surrounding stomach tissue. Itshould be understood by one of ordinary skill in the art that flanges510 may be of any configuration that allows flanges 510 to be connectedto one another in a generally parallel and stacked configuration whileallowing device 500 to be positioned as described below.

As flanges 510 act to control or inhibit the flow of chyme betweenstomach 30 and duodenum 50, the flow of gasses and other stomach fluidsis similarly inhibited. Along with the normal peristaltic action of thesurrounding tissue, such gasses may cause a buildup of pressure that maytend to force devices in a distal or proximal direction. Accordingly,flanges 510 may include one or more recesses, semicircular cutawaysections or radial slits (not shown) to aid in relieving such pressurebetween stomach 30 and duodenum 50 when device 500 is fully inserted byallowing such gasses to pass through the recesses. It is contemplatedthat the recesses or slits may be staggered circumferentially aboutflanges 510 without compromising the ability of the recesses to reducepressure. These radial slits or cutaways may also assist in permittingthe flow restrictor to be compressed into an “overtube” for endoscopicplacement and/or permit food to pass around flanges 510.

Flanges 510 preferably comprise one or more ribs 516 housed within arelatively flexible covering or frame 518. Ribs 516 are preferably stiffenough to provide support for the flexible covering 518 in the operativeposition and will define a pivot point near central tube 512 to allowribs 516 to pivot between the compact and operative positions. In anexemplary embodiment, ribs 516 and covering 518 are molded from asuitable biocompatible plastic, such as silicone. Ribs 516 have adurometer suitable for providing stiffness and support to the device,while frame 518 will have a softer durometer allowing flexibility andminimizing any adverse impact from tissue contact with the flanges.

Each flange 510 is movable between a first or operative position (FIGS.20 and 21) wherein flanges 510 extend radially outward substantiallyperpendicular to longitudinal axis 503 and a second or compact position(not shown) wherein flanges 510 bend downward such that they form asmall acute angle (almost parallel with) the longitudinal axis. In thisrespect, flow restrictor 502 operates in a similar manner as anumbrella. In the operative position, flanges 510 are designed to inhibitchyme flow from stomach 30 to pyloric sphincter 20. In addition, sinceflanges 510 have a larger outer diameter than the inner diameter ofpyloric sphincter 20 in its open position, they will prevent distalmovement of flow restrictor 502 through pyloric sphincter 20. In thecompact position, flanges 510 can be bent downward to substantiallyreduce the diameter of flow restrictor 502, allowing flow restrictor 502to be advanced endoscopically through the patient's esophagus (notshown) and into stomach 30, as discussed in more detail below.

As shown in FIG. 21, frame 518 of each of the flanges 510 has asubstantially annular shape. However, it will be recognized that flanges510 may have a variety of different shapes (e.g., square, triangular,diamond, rectangular, etc). In an alternative embodiment, the frames 518comprise multiple projections 550 extending radially outward fromcentral tube 512, e.g., a fan blade shape (see FIG. 24), a rose-petalshape and the like. As shown in FIG. 24, projections 550 of each flange510 are preferably circumferentially spaced from the projections 550 ofimmediately adjacent flanges along the longitudinal axis 503 of flowrestrictor 502. For example, projections 550 of the top or proximalflange 510 are circumferentially spaced from each of the projections 550in the next flange 510 below the top flange in the direction of thelongitudinal axis. In this manner, when projections 550 are foldeddownward in the compact configuration, they will not interfere with eachother, allowing the flow restrictor to conform to a smaller overalldiameter in the compact configuration. Alternatively, flanges 510 mayhave a configuration wherein the projections fold downward in a spiraldirection overlapping each other as they are folded into the compactconfiguration.

In any of these embodiments, flow restrictor 502 further comprises alocking mechanism for locking, biasing or otherwise securing ribs 516 inthe operative or expanded position. This ensures that the flowrestrictor will remain in the operative position while implanted in thepatient. In one embodiment shown in FIG. 21, the locking mechanismcomprises a plurality of leaf springs 520 coupled to ribs 516 at pivotpoints on central tube 512. Leaf springs 520 bias ribs 516 into theoperative position. Alternatively, ribs 516 may be designed to biasthemselves into the operative configuration. This embodiment isillustrated in FIGS. 22 and 23. As shown, ribs 516 each comprise a rod552 that extends radially outward in the operative configuration withinthe frame 518 of each flange 510 as discussed above. In addition, ribs516 comprise a curved pivot bar 554 that extend around a circular ring556 coupled to central tube 512. Curved pivot bar 554 operates to biasthe rod 552 of each rib 516 radially outward into the operativeconfiguration.

Alternatively, the locking mechanism may comprise a separate device thatengages the ribs and pivots them into the operative position. FIGS. 27and 28 illustrate such an embodiment. As shown, flow restrictor 502comprises a plunger 560 that is extendable through lumen 514 (see FIG.22) of central tube 512. Plunger 560 comprises a head 564 coupled to amain body 562 with multiple projections 566 extending radially outwardfrom body 562. In this embodiment, ribs 516 each define a rim 568extending through tube 512 into lumen 514. Projections 566 are designedto engage rims 568 of ribs 516 when plunger 560 is advanced into lumen514. Upon such engagement, plunger 560 will cause ribs 516 to pivot intothe operative position as shown in FIG. 27. Ribs 516 and thereby flanges510 will remain secured in the operative position so long as plunger 560remains within lumen 514 of tube 512. Plunger 560 can be locked intoplace within central opening by any suitable means. When the plunger 560is removed, ribs 516 are free to pivot such that the user can bendflanges 510 into the compact configuration for insertion or removal intoor from the patient.

FIGS. 25 and 26 illustrate one preferred embodiment of anchor 504 andthe proximal end of sleeve 508 in the expanded or operativeconfiguration. As shown, anchor 504 comprises a locking member 530 and atube 532 coupled to and extending distally from locking member 530.Locking member 530 preferably has a harder durometer than tube 532 toprovide for a secure anchor against the distal opening of the pyloricsphincter. This ensures that anchor 504 will remain in place within theduodenum 50 despite the natural peristalsis forces acting against anchor504. Tube 532 preferably has a funnel shape in the operativeconfiguration such that its proximal opening 534 is larger than itsdistal opening 535 to generally correspond to the narrowing shape of theGI tract distal of the pyloric sphincter. Anchor 504 further comprisesone or more bosses or ribs 542 extending from locking member 530 to thedistal end 535 of tube 532 at the junction between tube 532 and sleeve508. Bosses 542 provide structural support for anchor 504. Preferably,bosses 542 will have a slightly harder durometer than tube 532 andanchor 508, but a softer durometer than locking member 530. Bosses 542will provide an elastic spring such that they will provide distalresistance against natural peristalsis forces pressing tube 532 towardsthe pyloric sphincter. In addition, bosses 542 provide a naturalcoupling point for pyloric columns 506 as shown in FIG. 20.

Locking member 530 is designed to move the proximal end of tube 504between a first or compact position sized and shaped for advancementthrough the pyloric sphincter into the duodenum and a second oroperative position sized and shaped for anchoring against the pyloricsphincter at the proximal end of the duodenum to prevent movement ofanchor 504 through the pyloric sphincter. Locking member 530 ispreferably designed to allow for movement from the compact positiontowards the operative position, while preventing the reverse movementback towards the compact position. This locks anchor 504 into theoperative position after insertion into the patient. Locking member 530may be biased towards the operative position, or it may be designed torequire a force applied to locking member 530 to move it into theoperative position.

In one embodiment (shown in FIGS. 25 and 26), locking member 530comprises a ratchet having an annular sliding bar 536 coupled to theproximal end of tube 532. Bar 536 has a spiral configuration and isdesigned for circular displacement over itself. Bar 536 includes teeth538 that engage a catch (not shown) within a hollow section 540 of bar536 to allow for movement of bar 536 in the clockwise direction, butprevent reverse movement in the counterclockwise direction. Thus, as bar536 rotates clockwise, its outer diameter increases to increase theouter diameter of proximal opening 534 of tube 532. Bar 536 can beexpanded outward with a force applied to its inner surface (e.g., from aseparate balloon designed for such purpose as discussed in detailbelow). Hollow section 540 of bar 536 further comprises a tab 541 thatcan be removed to release bar 536 from teeth 538 and allow forcompression of anchor 504 during removal of the device (discussedbelow).

In an alternative embodiment, the locking member comprises a bar memberthat is movable between a substantially spiral configuration to asubstantially circular configuration. In exemplary embodiments, thelocking member will have multiple operative positions such that thephysician can appropriately size the anchor depending on the anatomy ofthe individual patient.

FIGS. 29 and 30 illustrate an alternative embodiment of an obesitydevice 600 that is inflated into the operative configuration. As shown,obesity device 600 comprises a flow restrictor 602 coupled to an anchor604 with a plurality of pyloric columns 606, and a hollow sleeve 608coupled to anchor 604 (only the proximal portion of sleeve 608 is shownin FIG. 29). In this embodiment, flow restrictor 602 comprises an outercollapsible shell 610 surrounding a hollow interior section 612.Collapsible shell 610 is movable between the inflated or operativeconfiguration shown in FIG. 29 to a deflated or collapsed configuration(not shown) for placement and removal from the patient. Collapsibleshell 610 has a roughly cylindrical inner core portion 614 with proximaland distal flanges 616, 618. Shell 610 preferably comprises a moderatedurometer silicon with a wall thickness of about 0.5-4.0 mm, preferablybetween about 1-3 mm. Flanges 616, 618 are rounded at the circumferenceto provide atraumatic contact with tissue and are spaced from each otherby about 10 to 40 mm, preferably between about 20 to 25 mm. Proximalflange 616 preferably has an outer diameter of about 40-60 mm and distalflange preferably has an outer diameter of about 25-35 mm. Flanges 616,618 preferably each comprise one or more semicircular cutaways 626 topermit food passage and retrograde fluid pressure relief.

Interior section 612 is fluidly coupled to a tube 620 having an opening(not shown) at the proximal surface of proximal flange 616 for inflatinginterior section 612 into the operative configuration shown in FIG. 29.Tube 620 comprises a one-way valve (not shown), such as an umbrellavalve, to ensure that fluid delivered into interior section 612 will notpass out of tube 620 after flow restrictor 602 has been inflated. Coreportion 614 has an outer diameter of approximately 3-15 mm, preferablybetween about 4 to 6 mm, and a length of about 25-35 mm when interiorsection 612 is fully inflated. Flow restrictor 602 preferably includes apair of protuberances 638 at its proximal end that can be grabbed by asimple grasping instrument to pull/manipulate the device as requiredduring implantation/removal.

As shown in FIG. 30, a hollow tube 622 extends through the central axisof flow restrictor 602. Tube 622 preferably comprises a hard plasticwall with an interior diameter of about 2-4 mm. Tube 622 providesstiffness to flow restrictor 602 as well as providing a lumen for guidewire and instrument access through flow restrictor 602 to the distalcomponents of obesity device 600 (discussed below). In addition, a fluidlumen 624 extends through flow restrictor 602 to allow for fluid passagethrough one of the fluid columns 606 to inflate anchor 604 as discussedbelow. Fluid lumen 624 will also comprise a one-way valve (not shown) toensure that anchor 604 remains inflated during operation of the device.Alternatively, interior 612 of flow restrictor 602 may be fluidlycoupled to the interior of anchor 604 or a separate exterior fluid line(not shown) may be used to deliver fluid into anchor 604 (discussed inmore detail below with respect to the embodiment shown in FIGS. 31-32).

In this embodiment, anchor 604 comprises an inflatable annular tube 630coupled to an internal support ring 632 and a funnel 634. Inflatabletube 630 is movable between a collapsed position for advancement throughthe pyloric sphincter and an expanded or inflated position wherein tube630 has an outer diameter that is greater than the maximum diameter ofthe pyloric sphincter in its open position to prevent proximal migrationof anchor 604 through the pyloric sphincter. Internal support ring 632has a diameter slightly less than the maximum diameter of the pyloricsphincter and comprises a harder durometer silicone to provide stiffnessand support to tube 630. In particular, support ring 632 ensures thattube 630 maintains a substantially circular shape as it encountersintestinal forces such that the tube 630 cannot be squeezed back throughpyloric sphincter by the peristalsis forces within the small intestine.

Inflatable tube 630 is preferably fluidly coupled to one or more of thebosses 636 extending from proximal to distal ends of anchor funnel 634.Bosses 636, in turn, are fluidly coupled to one or more of the pyloriccolumns 606, i.e., through internal lumens in one or more of the bosses636 and columns 606. Bosses 636 preferably have some elasticity and willprovide stiffness to the overall funnel shape such that anchor 604cannot be twisted into a smaller configuration for proximal migrationthrough the pyloric sphincter. The boss 636 that includes a fluid lumenis fluidly coupled to internal lumen 624 in flow restrictor 602.Internal lumen 624 preferably has an inlet (not shown) at the proximalend of flow restrictor 602 allowing the physician to deliver fluid tolumen 624 and thus inflatable tube 630. In an exemplary embodiment, theone-way valve will be positioned at the proximal end of internal lumen624 rather than within inflatable tube 610 as discussed above. In thisembodiment, the one-way valve will preferably have a mechanism that willallow for opening of the value and removal of fluid from device 600during removal of device 600 from the patient (discussed in detailbelow).

In addition to, or as an alternative to, the one-way valve, a curablefluid, such as silicone, may be injected into the fluid pathway afterthe saline. The curable fluid will cure and harden, thereby preventingany fluid egress from the interior of tube 630. In another embodiment,the inflatable members of the flow restrictor and/or the anchor maycomprise a material that self-seals when punctured with a very sharpsmall instrument such as a syringe. In this embodiment, the inflatablemembers of the obesity device may simply be inflated with a syringe andthen self-sealed by the material to prevent fluid egress.

Referring now to FIGS. 31 and 32, another preferred embodiment of a flowrestrictor 660 is illustrated. Similar to the previous embodiment, flowrestrictor 660 comprises an inflatable outer membrane 662 surrounding ahollow interior 664 such that membrane 662 can be inserted into thepatient's stomach in a deflated or collapsed configuration and theninflated into the operative configuration. In this embodiment, membrane662 comprises a relative thin flexible material, such as silicone,preferably having a wall diameter of about 0.1 to 1 mm thick. Flowrestrictor 660 further comprises proximal and distal sheets 666, 668that may be molded with, or glued to, membrane 662 as discussed.Alternatively, sheets 666, 668 and membrane 662 may be constructed as asingle piece such that membrane 662 constitutes the entire outer wall ofthe structure. Proximal and distal sheets 666, 668 preferably have aslightly greater thickness (e.g., preferably between about 0.5 mm to 2.0mm) and stiffness than membrane 662 to provide flow restrictor 660 withsupport and to hold its annular shape in the operative configuration.

Flow restrictor 660 further comprises one or more ribs or bosses 670 andone or more support members 672 extending along membrane 662 fromproximal sheet 666 to distal sheet 668. Bosses 670 and support members672 preferably comprise a slightly thicker silicone material (i.e.,preferably about 1.0 mm to 2.0 mm thick) and provide further support tothe overall structure of flow restrictor 660. In an exemplaryembodiment, support members 672 have an arcuate shape and formcut-a-ways or recesses 674 in the otherwise conical shape of flowrestrictor 660. Recesses 674 provide paths for passage of chyme instomach 30 past flow restrictor 660 to the pyloric sphincter and forpassage of gases and/or fluids between the stomach and the duodenum. Inthe exemplary embodiment, bosses 670 are formed on the outside surfaceof membrane 662 and support members 672 are formed within the innersurface of membrane 662. However, it will be recognized by those skilledin the art that a variety of different configurations can be employed toprovide structure to flow restrictor 660 in the inflated configuration.

Flow restrictor 660 further includes a central tube 676 having an innerlumen 678 extending along its longitudinal axis and a one-way valve 680with an opening in distal sheet 666. Central tube 676 preferably has awall thickness of about 0.1 mm to 1 mm and an inner diameter of betweenabout 2 mm to 4 mm. Central tube 676 provides additional structuralsupport for flow restrictor 660 and also provides a lumen for passage ofa guidewire and/or other instruments, such as a gastroscope. One-wayvalve 680 is configured for coupling to a fluid tube (not shown) fordelivering a fluid, such as saline, to the interior 664 of membrane 662for inflation of flow restrictor 660.

In reference to FIGS. 33-39, a method of implanting and removing anobesity device 800 (similar to one of, or a combination of, theembodiments shown in FIGS. 19-32 according to the present invention willnow be described. While the description of this method will bespecifically directed to the embodiments illustrated above, it will beunderstood by those skilled in the art that this method (or similarmethods) can be used to implant and remove all of the embodiments of thepresent invention, including embodiments or designs that may not bespecifically described or illustrated herein.

Device 800 enters and exits the patient through esophagus 702 and isultimately positioned in its operative state, wherein pyloric columns606 (shown in FIG. 29) extend through pyloric sphincter 20 (e.g., seeFIG. 36). In certain embodiments, flow restrictor 602 (FIG. 29) andanchor 604 (FIG. 29) are separately encapsulated for implantation suchthat each may be independently released. Ideally, anchor 604 is releasedfirst such that anchor 604 and sleeve 608 (FIG. 29) are advanced as asingle uninflated structure into the duodenum, coupled to flowrestrictor 602 by columns 606. The flow restrictor 602 is then inflatedfollowing the proper positioning of anchor 604 and sleeve 608. In otherembodiments, the flow restrictor and anchor are not encapsulated and aresimply advanced through the esophagus or the overtube in their deflatedconfigurations.

Initially, a gastroscope 706 is lubricated, inserted into patient'smouth 707, and fed through esophagus 702 and the gastroesophageal (“GE”)junction into stomach 20, as shown in FIG. 33. Gastroscope 706 ispreferably approximately 9.8 millimeters in length, and preferably hasapproximately a 2.8 millimeter working channel and suitable viewing andrecording equipment, for example. It will be understood that tools andcomponents that are described as being passed through or inserted intogastroscope 706 are passed through or inserted into its working channel.A lubricant such as Surgilube or equivalent may be provided as needed tolubricate the obesity device and/or any of the associated surgicalequipment.

Gastroscope 706 should ultimately be positioned such that its distal end708 is adjacent to pyloric sphincter 20. Preferably, a guidewire 722 ishydrated and inserted through gastroscope 706. Guidewire 722 is passedthrough pyloric sphincter 20, which may be aided by manipulation ofgastroscope 706. It may also be beneficial to pass a distal end 708 ofgastroscope 706 through pyloric sphincter 20 in order to maneuverguidewire 722 through same. There should preferably be at least about30-40 centimeters of the length of guidewire 722 passed distally throughpyloric sphincter 20 and into small intestine 40 so that any furthermovement of guidewire 722 during the insertion procedure does not resultin the accidental removal of the distal end of guidewire 722 to aposition proximal of pyloric sphincter 20. Of course, the length ofguidewire 722 that should preferably be passed distally through pyloricsphincter 20 may vary according to different patients and/or proceduresand may be less or more than 30-40 centimeters. After guidewire 722 isappropriately positioned, gastroscope 706 is removed from the patient.

Referring now to FIG. 34, an overtube 730 is positioned over theguidewire 722 and advanced through the esophagus and into the patient'sstomach. Overtube 730 typically has an inner diameter of approximately16 mm. Obesity device 800 is lubricated and positioned over theguidewire 722 outside of the patient. Once overtube 730 is positionedwithin stomach 30, a small steerable scope (not shown) is advancedthrough overtube 730 into stomach 30 through the pylorus and into theproximal portion of the duodenum. The scope is used to confirm thetissue of the stomach, pylorus and duodenum are robust and show notovert signs that they will not tolerate the device. In an exemplaryembodiment, a small tube (not shown) may be inserted into the pylorus.The tube includes a distal inner tube-shaped balloon (not shown) thatexpands to a known diameter with a known volume of saline. Inconjunction with the scope images and other prior imaging data, thisinstrument is used to determine the appropriate size of obesity device800 to be used, particularly the appropriate size of anchor 604.

Once the appropriate size obesity device 800 is selected, a pusher rod732 is used to push obesity device 800 into stomach 30. In the exemplaryembodiment, flow restrictor 660 is encapsulated within a proximalcapsule 734 and both anchor 604 and sleeve 608 are preferablyencapsulated within a distal capsule 736 to help advance device 800through overtube 730. It should be noted that it may not be necessary toencapsulate flow restrictor 660 and anchor 604 in order to advance themthrough overtube 730. In this case, these components will simply beadvanced through overtube 730 in their deflated configurations.

Referring now to FIG. 35, distal capsule 736 is removed and anchor 630and sleeve 608 are advanced with pusher rod 732 (not shown in FIG. 35)through the pylorus and into the proximal portion of the duodenum. Thismay require the use of a dilator (not shown) to maintain the pylorus inits maximum diameter. Once positioned properly, a fluid, such as salineor another appropriate fluid is injected through an external tube (notshown) and one-way valve into the expandable membrane to inflate themembrane to its expanded or operative configuration. The external tubewould then be cut by a pair of scissors or other such instrument thatcan be advanced through the working channel of overtube 730.Alternatively, the fluid may be delivered through a syringe directlyinto the membrane or through an internal tube within the flow restrictorthat is coupled to the interior of the membrane as described previously.

Once the anchor 630 has been inflated into its operative configuration,knob 750 at the distal end of sleeve 608 is grasped by a suitablegrasping instrument and advanced downwardly through the duodenum andinto the jejunum. When sleeve 608 has reached its maximum length,perforation 752 is torn and sleeve 608 is fully deployed. Knob 750 andperforation 752 can then be removed from the patient. Alternatively,sleeve 608 may be positioned either before anchor 630 has been inflatedor after flow restrictor 660 has been inflated as described below.

Referring now to FIG. 36, proximal capsule 734 (shown in FIG. 35) isthen disengaged from flow restrictor 660 and removed from the patient. Afluid, such as saline, is injected through inlet 680 (see FIG. 31) intothe interior portion 664 of flow restrictor 660 to inflate flowrestrictor 660 into its operative configuration. Obesity device 800should now be in its final position with flow restrictor 660 in pyloricantrum 740 of stomach 30 and expandable membrane 642 of anchor 630 justdistal to the pyloric sphincter 20. A gastroscope and/or fluoroscope(not shown) may be used to confirm the final placement of device 800.Once device 800 is in place, guidewire 722 and overtube 730 can beremoved from the patient.

Referring now to FIGS. 37-39, a method for removing obesity device 800according to the present invention will now be described. As shown inFIG. 29, overtube 730 is advanced through the esophagus and intoposition within the stomach 30 of patient and a gastroscope (not shown)is deployed through overtube 730 in a suitable position for the surgeonto view the procedure. A sharp instrument 760, such as scissors or thelike, is advanced through overtube 730 into stomach 30. Sharp instrument760 is used to puncture flow restrictor 660 such that the fluid withininterior portion 664 of flow restrictor 660 exits interior portion 664into the stomach to deflate flow restrictor 660. Alternatively, asyringe or similar suction device (not shown) may be attached to inlet680 to withdraw the fluid from flow restrictor 660.

Referring now to FIG. 38, flow restrictor 660 is preferably positionedto the side of antrum 740. A grasping or cutting instrument 762 isadvanced through overtube 730 to cut each of the pyloric columns 606 todetach flow restrictor 660 from the distal portion of device 800. Thelast column 606 that is severed will be held by grasping instrument 762to ensure that anchor 630 and sleeve 608 do not migrate in the distaldirection after being detached from flow restrictor 660. At this point,a grasping tool or snare (not shown) is advanced into stomach 30 to grabone or both of protuberances 638 on the proximal surface of flowrestrictor 660. Flow restrictor 660 is then pulled through overtube 730and removed from the patient.

Referring now to FIG. 39, a grasping instrument 764 is then advancedthrough the pyloric sphincter 20 to grasp a ball element attached towire embedded in the inner membrane of the ring-inner tube structure.Grasping instrument 764 is pulled to cause the fluid within membrane 642to exit membrane 642 and deflate anchor 630. Grasping instrument 764 maythen be used to pull anchor 630 and sleeve 608 into stomach 30. Inalternative embodiments, membrane 642 is fluidly coupled to a lumen (notshown) within flow restrictor 660 through one or more of the boss(es)635 and column(s) 606. In these embodiments, cutting of the column(s)606 will automatically deflate membrane 642.

Once anchor 630 and sleeve 608 are within stomach 30, they may be slicedup and removed or removed as a single unit. Subsequent to the removal ofobesity device 800, a scope (not shown) can be used to determine if anytissue injury or insult that has been sustained by the implantation,use, or removal of device 800. Provided no additional access to thestomach, pylorus, or duodenum is required, removal of the scope andovertube 730 conclude the procedure.

Although the invention herein has been described with reference toparticular embodiments, it is to be understood that these embodimentsare merely illustrative of the principles and applications of thepresent invention. It is therefore to be understood that numerousmodifications may be made to the illustrative embodiments and that otherarrangements may be devised without departing from the spirit and scopeof the present invention as defined by the appended claims.

1. A method for treating a wound in a diabetic patient comprising:removably introducing a hollow sleeve through a natural orifice of thepatient to a target site in the duodenum to inhibit contact betweenchyme passing therethrough and at least a portion of an inner surface ofthe duodenum; maintaining the hollow sleeve within the duodenum for asufficient period of time to reduce a blood glucose level in thepatient.
 2. The method of claim 1 wherein the hollow sleeve ismaintained within the duodenum for a sufficient period of time toincrease peripheral vascular perfusion in the patient and acceleratehealing of the wound.
 3. The method of claim 1 wherein the hollow sleeveis maintained within the duodenum for a sufficient period of time toelevate an immune system response of the patient and accelerate healingof the wound.
 4. The method of claim 1 wherein the hollow sleeve ismaintained within the duodenum for a sufficient period of time todecrease insulin resistance within the patient.
 5. The method of claim 1wherein the hollow sleeve is maintained within the duodenum for asufficient period of time to increase leukocyte activity in the patient.6. The method of claim 1 wherein the hollow sleeve is maintained withinthe duodenum for a sufficient period of time to increase vascularendothelial growth factors in the patient's vascular tissue andaccelerate healing of the wound.
 7. The method of claim 1 wherein thehollow sleeve is maintained in the duodenum until the wound has closed.8. The method of claim 1 wherein the blood glucose level is reduced tobelow 150 mg.
 9. The method of claim 1 wherein the blood glucose levelis reduced to below 125 mg.
 10. The method of claim 1 wherein theinternal bypass device is maintained within the duodenum for asufficient period of time to reduce a fasting blood glucose level of thepatient to below 99 mg.
 11. The method of claim 1 wherein the wound is adiabetic foot ulcer.
 12. The method of claim 1 wherein the maintainingstep is carried out by anchoring the hollow sleeve in position withinthe duodenum.
 13. The method of claim 1 wherein the internal bypassdevice is maintained within the duodenum for at least three weeks. 14.The method of claim 1 wherein the internal bypass device is maintainedwithin the duodenum for at least two months.
 15. The method of claim 1wherein the removably introducing step comprises: advancing a duodenalanchor portion of the internal bypass device through an esophagus, astomach and a pylorus into a duodenum of the patient; and extending ahollow sleeve of the internal bypass device through at least a portionof the duodenum.
 16. The method of claim 15 wherein the removablyintroducing step further comprises advancing a gastric anchor portion ofthe internal bypass device through the esophagus and into the stomach ofthe patient.
 17. The method of claim 16 wherein the maintaining step iscarried out by expanding the duodenal anchor portion within the duodenumand expanding the gastric anchor portion within the stomach of thepatient such that the hollow sleeve remains in position within theduodenum.
 18. A method of treating a chronic lower limb wound in apatient having a lack of innate ability to regulate glucose levels,comprising positioning a flexible sleeve between chyme exiting a stomachof the patient and at least a portion of an inner surface of theduodenum for a sufficient period of time to decrease a blood glucoselevel of the patient.
 19. The method of claim 18 wherein the sleeve ismaintained in position within the duodenum until the blood glucose levelof the patient is normalized.
 20. The method of claim 18 wherein thesleeve is maintained in position within the duodenum until an increasein peripheral blood perfusion occurs within the patient.
 21. The methodof claim 18 wherein the sleeve is maintained in position within theduodenum until an increase in leukocyte activity occurs within thepatient.
 22. The method of claim 18 wherein the sleeve is maintained inposition within the duodenum until the chronic lower limb wound isclosed.
 23. A method of increasing the perfusion of blood at the site ofa chronic lower limb wound in a patient having a lack of innate abilityto regulate glucose levels, comprising positioning a flexible sleevebetween chyme exiting the patient's stomach and at least a portion of aninner surface of the patient's duodenum for a sufficient period of timethat permits normalization of glucose levels in the patient.
 24. Amethod of decreasing the time to wound closure of a chronic lower limbwound in a patient having a lack of innate ability to regulate glucoselevels, comprising: removably introducing a flexible sleeve betweenchyme exiting the animal's stomach and at least a portion of an innersurface of the animal's duodenum by delivering the flexible sleevethrough a natural orifice of the animal, maintaining said sleeve withinthe duodenum for a period of time that permits at least one of thefollowing to occur; normalization of glucose levels in the patient, anincrease in peripheral vascular perfusion, and an increase in leukocyteactivity.
 25. The method of claim 24 further comprising stabilizing saidflexible sleeve by positioning a pair of elements on either side of theanimal's pyloric sphincter, wherein said elements are too large to passacross the pyloric sphincter, and wherein said elements are flexiblycoupled to the flexible sleeve and to one another.
 26. A method ofenhancing peripheral vascular perfusion in a patient, comprisingpositioning a flexible sleeve between chyme exiting the patient'sstomach and at least a portion of an inner surface of the patient'sduodenum for a period of time that permits at least one of the followingto occur: normalization of glucose levels in the patient, an increase inleukocyte activity, and an increase in vascular endothelial growthfactor in the vascular tissue of the patient.
 27. A method of increasingleukocyte activity in a patient having a lack of innate ability toregulate glucose levels, comprising positioning a flexible sleevebetween chyme exiting the patient's stomach and at least a portion of aninner surface of the patient's duodenum for a period of time thatpermits at least one of the following to occur in the patient:normalization of glucose levels, and an increase in peripheral bloodperfusion.
 28. A method of increasing the amount of vascular endothelialgrowth factor present in the tissue of a patient having (i) a lack ofinnate ability to regulate glucose levels, and (ii) diminishedperipheral vascularity, comprising positioning a flexible sleeve betweenchyme exiting the patient's stomach and at least a portion of an innersurface of the patient's duodenum for a period of time that permits atleast one of the following to occur in the patient: normalization ofglucose levels, an increase in peripheral blood perfusion, and anincrease in leukocyte activity.
 29. A method of enhancing the activityof circulating leukocytes in a patient having a lack of innate abilityto regulate glucose levels, comprising positioning a flexible sleevebetween chyme exiting the patient's stomach and at least a portion of aninner surface of the patient's duodenum for a period of time thatpermits at least one of the following to occur in the patient:normalization of glucose levels; and an decrease in the HbA1C levels.30. A method of reducing HbA1C levels in a patient having a lack ofinnate ability to regulate glucose levels, comprising positioning aflexible sleeve between chyme exiting the patient's stomach and at leasta portion of an inner surface of the patient's duodenum for a period oftime that permits at least one of the following to occur in the patient:normalization of glucose levels, an increase in peripheral bloodperfusion, and an increase in leukocyte activity.
 31. A method ofreducing the rate of infection in a chronic lower limb wound of apatient having a lack of innate ability to regulate glucose levels,comprising positioning a flexible sleeve between chyme exiting thepatient's stomach and at least a portion of an inner surface of thepatient's duodenum for a period of time that permits at least one of thefollowing to occur in the patient: normalization of glucose levels, anincrease in peripheral blood perfusion, an increase in leukocyteactivity, and wound closure.